PT Dual Language Rev 1

8/19/2019 PT Dual Language Rev 1

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NDT TRAINING PROGRAM

LIQIUD PENETRANT METHOD(Dual Language)

ASNTContinuing

EducationIn Nondestructive

Testing

The American Society for Nondestructive Testing


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LIQUID PENETRANT METHODPage 1 of 42

Rev: 01 Prepared by: Arif 101008

Table Content

Lesson 1.................................................................. 2

Lesson 2.................................................................. 9

Lesson 3.................................................................. 16

Lesson 4.................................................................. 24

Lssson 5.................................................................. 30

Lesson 6.................................................................. 37

Lesson 7.................................................................. 48


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LIQUID PENETRANT METHODPage 2 of 42


LESSON – 1

Liquid penetrant testing is anondestructive means of locatingsurface discontinuities based onc a p i l l a r i t y or c a p i l l a r y a c t i o n .

In the liquid penetrant method, theliquid is applied to the surface of thespecimen and sufficient time is allowedfor penetration of surfacediscontinuities. If the discontinuity issmall or narrow as in a crack or pinhole,capillarity assists the penetration.

Pengujian cairan penetrant adalah salahsatu metode pengujian tanpa merusakuntuk melokalisasi (menemukan) cacat-cacat permukaan berdasarkan padak a p i l a r i t a s atau c a p i l l a r y a c t i o n .Dalam metoda liquid penetrant, cairandiaplikasikan pada permukaan benda ujidan diberikan waktu yang cukup untukpenetrasi pada cacat permukaan.Jika cacat kecil atau sempit seperti retakatau lobang kecil (pinhole), kapilaritasmembantu penetrasi

After sufficient time has passed for thepenetrant to enter the discontinuity, thesurface of the part is cleaned, capillaryaction is again employed to act as ablotter to draw penetrant from thediscontinuity .

Setelah waktu yang cukup untukpenetrant masuk dalam cacat,permukaan benda uji dibersihkan,capillary action terjadi lagi sebagai blotteryang menarik penetrant dari cacat


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LIQUID PENETRANT METHODLesson 1 Page 3 of 42


To insure visibility, the liquid penetrantcontains either a colored dye easily seenin white light or a fluorescent dye visibleunder black (ultraviolet) light.

Untuk dapat dilihat, cairan penetrantberisi salah satu, cairan berwarna yangbisa dilihat dengan sinar biasa atauwarna fluorescent yang bisa dilihatdengan lampu ultraviolet

Discontinuities that are subsurface inone stage of production could be opento the surface at another stage. such as

after grinding or machining.

Cacat yang di bawah permukaan dalamsatu proses produksi dapat dibuka padapermukaan, pada proses berikutnya.

seperti setelah penggerindaan ataupengerjaan dengan mesin.


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Non-metallic inclusions and porosity inthe ingot may cause stringers, seams.forging laps. cold shuts, and the like asthe billet or slab is processed in themanner shown below

Inklusi non-metallic dan porositas padaingot dapat menyebabkan stringers,seams, forging laps, cold shuts, dan jugapada billet atau slab yang diproses sbb :

Anything that could block the penetrantfrom entering the discontinuity must beremoved.

Semua yang dapat menghalangipenetrant memasuki cacat harusdibersihkan


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A list of contaminants that must beremoved would include dirt, grease,rust. Scale. Acids. And even water.The cleaning solvent used must bevolatile (readily vaporized) so that iteasily evaporates out of thediscontinuity and does not dilute thepenetrant.

Daftar contaminant yang harusdibersihkan termasuk kotoran, oli, karat,kerak, acid dan air.Pembersih solvent yang digunakan harusmudah menguap, sehingga denganmudah menguap keluar dari cacat dantidak mengencerkan penetrant.

Surface preparation by the s h o t ors a n d b l a s t i n g is not recommendedDiscontinuities that were open to thesurface may be closed by the shot orsandblasting

Persiapan permukaan dengan s h o t ataus a n d b l a s t i n g tidak direkomendasiCacat yang terbuka pada permukaandapat tertutup oleh shot atausandblasting

Historically. Penetrant inspection wascalled the “oil and whiting method”, asit used kerosene and white powder forthe inspection of railroad parts.However, in the past 40 years theprocess has been improvedtremendously to the point where it is areliable and accurate inspectiontechnique.The liquid penetrants used innondestructive testing can be

categorized by the t y p e o f t h e d y e they contain.1. Vi s i b l e d y e p e n e t r a n t s contain a

colored (usually red) dye.

2. Fl u o r e sc en t p e n e t r a n t s contain afluorescent dye.

3. D u a l s e n s i t i v i t y p e n e t r a n t s contain a combination of visible andfluorescent dyes.

Menurut sejarah, inspeksi penetrantdisebut “metoda minyak dan pemutih"seperti digunakan minyak tanah danbedak putih untuk inspeksi rel kereta api.Bagaimanapun. setelah 40 tahun prosestelah ditingkatkan pada tingkat menjadisuatu teknik inspeksi yang dapatdipercaya dan akurat

Cairan penetrants yang digunakan dalampengujian tanpa merusak digolongkan

oleh j e n i s k a n d u n g a n w a r n a n y a 1. Vi s ib l e d y e p e n e t r a n t s berisi cairan

berwarna ( pada umumnya merah)2. F l u o r e s c e n t p e n e t r a n t s berisi

cairan fluorescent (berpendar)3. D u a l s e n s it i v i t y p e n e t r a n t s berisi

kombinasi cairan visible danfluorescent

Penetrants can be further categorized

by the processes used t o r e m o v e t h ee x c e ss p e n e t r a n t from the specimen

Penetrants selanjutnya digolongkan

sesuai proses yang digunakan u n t u km e m b e r s i h k a n k e l eb i h a n p e n e t r a n t pada benda uji


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1. W a t e r w a sh a b l e penetrants areeither self-emulsifying or removablewith plain water.

2. P o s t e m u l s i f ie d penetrants requirea separate emulsifier to make thepenetrant water washable.

3. So l v e n t - r e m o v a b l e penetrant mustbe removed with a solvent which istypical when using visible dye inpressurized spray cans.

1. W a t e r w a sh a b l e penetrants adalahsalah satu self-emulsifying ataudapat dibersihkan dengan air

2. P o s t e m u l s i f ie d penetrantsmemerlukan emulsifier terpisahemulsifier untuk membuat penetrantdapat dibersihkan dengan air

3. So l v e n t - r e m o v a b l e penetrant yangharus dibersihkan dengan solvent(solvent) yang sejenis denganpenggunaan visible dye dalam kalengbertekanan

The flow chart below illustrates the

processing sequence with v i s i b l e d y ea n d f l u o r e s c en t p e n e t r a n t s .

Diagram alur di bawah menggambarkan

langkah proses dengan v i s i b l e d y e d a nf l u o r e sc e n t p e n e t r a n t s .

D u a l s e n s i t i v i t y p e n e t r a n t s wouldfollow a processing sequence similar tothat shown below

D u a l s e n s i t i v i t y p e n e t r a n t akanmengikuti urutan proses sama denganyang ditunjukkan di bawah


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The selection of the best process. Aslisted on pages 4 and 5. depends on

1. Sensitivity required2. Number of articles to be tested3. Surface condition of part being

inspected4. Configuration of test specimen5. Availability of water. Electricity.

Compresses air. Suitable testing.

Pemilihan proses yang terbaik sepertiyang terdaftar pada halaman 4 dan 5.tergantung pada1. Sensitivitas yang diperlukan2. Jumlah benda uji yang diuji3. Kondisi permukaan benda uji4. Bentuk benda uji5. Ketersediaan air. listrik. kompresor.

area pengujian yang sesuai

Penetrant testing is success fully usedon metals such as aluminum.Magnesium. Brass. Copper. Cast iron.Stainless steel. Titanium. And mostother common alloys.It can also be used to test othermaterials. Including ceramics. Plastics.Molded rubber. Powdered metal productsor glass.Penetrant testing is limited by itsinability to test materials withdiscontinuities that are not open to thesurface or having an extremely poroussurface.

Pengujian penetrant berhasil digunakanpada metal seperti aluminum.magnesium. kuningan. tembaga. besicor. baja tahan-karat. titanium. danhampir semua logam campuran umum.Juga dapat digunakan untuk mengujimaterial lain, termasuk keramik. plastik.karet. produk metal (powder) atau kaca

Pengujian penetrant terbatas padaketidakmampuan pengujian materialdengan cacat yang tidak terbuka padapermukaan atau mempunyai permukaanyang poros (berpori-pori)


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Quiz 1

____ 1. Nonmetallic inclusions and porosity in the steel ingot are commonly foundusing liquid penetrant inspection techniques.

____ 2. Type II penetrants, according to our test, are those containing afluorescent dye.

____ 3. Because of the capillary action of penetrants, this process of inspectionworks well on parts with very porous surfaces

____ 4. When doing a liquid penetrant test. the configuration of the specimen haslittl effect on the effectiveness of the test.

____ 5. Liquid penetrant inspection can be used only metals such as aluminiumand steel.

____ 6. The penetrant inspection method is used only on the finished product ____ 7. Oil and whiting are the names of the two men who invented the penetrant

test method. ____ 8. The first important step in penetrant testing is surface preparation. ____ 9. One of the most common contaminants in the penetrant method is water. ____ 10. The most common method of surface preparation testing is sandblasting. ____ 11. Chemical etching is sometimes used to remove smeared metal from a

surface to open discontinuities. ____ 12. Some subsurface defects can be located with the highly sensitive type II

penetrants ____ 13. Blow holes and gas porosity may be detected with the penetrant method. ____ 14. Solvent cleaning is a common method of surface cleaning parts before

penetrant testing. ____ 15. The one major limitation to penetrant testing is that the part must be

metallic ____ 16. Grease and rust would usually be considered a contaminant on the surface

of a test piece. ____ 17. To locate a defect with penetrant testing, the defect must be open to the

surface. ____ 18. It is considered advantageous for a liquid penetrant material to have low

tension and high capillarity.


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LESSON-2

This lesson discusses the equipment andmaterial required to perform the variouspenetrant tests and the required pre andpost-test cleaning.

Pelajaran ini mendiskusikan peralatandan material yang diperlukan untukmelaksanakan berbagai pengujianpenetrant dan pembersihan yangdiperlukan sebelum. dan setelahpengujian

P r o p e r c l e a n i n g is essential to liquidpenetrant testing for two reasons.

1. If the specimen is not clean and dry.Penetrant testing is ineffective

2. If all traces of penetrant materialsare not removed after the test, theymay have a harmful effect on thespecimen (chlorine and sulfur mayaffect some alloys)

P em b e r s ih a n y a n g t e p a t adalahpenting pada pengujian penetrantdengan dua pertimbangan.1. Jika benda uji tidak bersih dan

kering, pengujian penetrant tidak

efektif2. Jika sisa penetrant tidak dibersihkansetelah pengujian, dapat berdampakmerusak benda uji (khlor danbelerang dapat berdampak padabeberapa logam campuran)

I m m e r s i o n t a n k s an d d e t e r g en ts o l u t i o n s are common means ofassuring that a specimen surface is bothphysically and chemically clean.

T an g k i p e r e n d a m d a n a i r s a b u n umum untuk meyakinkan permukaanbenda uji telah bersih secara fisik dandari chemical

Va p o r d e g r e a s i n g is particularlyeffective in the removal of oil, greaseand similar organic contaminationhowever, certain alloys have an affinityfor specific elements used in vapordegreasing and if exposed to them maybecome structurally damaged.

U a p s o l v e n t sangat efektif untukmembersihkan minyak, stempet dankotoran organik, bagaimanapun.campuran logam tertentu mempunyaikepekaan dengan unsur-unsur tertentuyang digunakan dalam penguapan dan

jika digunakan dapat menimbulkankerusakan struktur

St e a m c le a n i n g is particularlyadaptable to the cleaning of large,unwieldy articles.

P e n c u c i a n d e n g a n u a p dapatdigunakan untuk pembersihan benda ujiyang besar dan susah

S o l v e n t c l e a n i n g may be used inimmersion tanks or may be used in awipe-on and wipe-off technique. Solventcleaning is usually less effective than theprevious methods of cleaning.

S o lv e n t s o l v e n t dapat digunakan dalamtangki perendam atau dengan teknikpengelapan. Solvent pada umumnyakurang efektif dibanding metodapembersihan sebelumnya

R u s t a n d s u r f a c e s c a l e can beremoved by any good commerciallyavailable acid or alkaline rust removerfollowing manufacturer`s directions.

K a r a t d a n k e r a k permukaan dapatdibersihkan dengan acid atau pembersihalkali dengan mengikuti petunjuk pabrikpembuat

P a in t r e m o v a l is often done in

dissolving-type hot-tank paint strippers,bond release, or solvent paint strippers.

P em b e r s ih c a t sering dilakukan dalam

dissolving-type hot-tank pelepas cat,pelepasan lapisan atau solvent cat.


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E t c h i n g is effective for use on articlesthat have been ground or machined.

This process uses an acid or an alkalinesolution to open up grinding burrs andremove metal from surfacediscontinuities.

P e n g e t s a a n ( e t s a ) efektif untukdigerinda halus pada benda uji yangtelah dihaluskan atau dimachining.Proses ini menggunakan cairan acid ataualkali untuk membuka grinding burrsdan membersihkan metal daripermukaan cacat

S u r f a c e c l e a n i n g p r o c e s s e s t o b ea v o i d e d include blast (shot. Sand. Rit.Or pressure). Liquid honing, emerycloth, wire brushes and metal crapers.These processes tend to closediscontinuities by peening or cold

working the surface of the specimen.

P r o se s p e m b e r s ih a n p e r m u k a a ny a n g d i h i n d a r i termasuk blast ( shot,sand, grit atau tekanan). Cairan honing (pengasah), ampelas, sikat kawat danscraper. Proses ini cenderung menutupcacat dengan pukulan atau cold working

pada permukaan benda uji.P en e t r a n t t e s t e q u i p m e n t( s t a t i o n a r y )Stationary equipment used in liquidpenetrant testing varies in size andlargely dependent upon the size of thetest specimen, depending on the typeand processes used. A stationary systemcould include the following:1. Pre-cleaning station (usually in

remote area)

2. Penetrant station (tank)3. Drain station4. Emulsification station (tank)5. Rinse station (tank)6. Developing station (tank)7. Drying station (usually oven)8. Inspection station (enclosed booth or

table with proper lighting)9. Post-cleaning station (usually in

remote area)

P e r a l a t a n p e n g u j i a n p e n e t r a n t( d u d u k / s t a t io n a r y )Peralatan duduk/stationary untukpengujian penetrant bervariasi dalamukuran dan besarnya bergantung padaukuran benda uji, bergantung pada jenisdan proses yang digunakan. Sistemduduk/stationay dapat termasuk sbb :1. Tempat pre-cleaning (umumnya

tempat terbuka)

2. Tempat penetrant (tangki)3. Tempat pengatusan4. Tempat emulsifikasi (tangki)5. Tempat pembilasan (tangki)6. Tempat developing (tangli)7. Tempat pengeringan (open)8. Tempat inspeksi (meja dengan

penerangan yang cukup)9. Tempat pembersihan akhir (tempat

terbuka)


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P en e t r a n t t e s t e q u i p m e n t (portable)Both visible and fluorescent dyepenetrants are available in kits whichcan be used at a remote location orwhen testing a small portion of a largearticle.

P e r a l a t a n p e n e t r a n t (portable)Keduanya visible dan fluorescentpenetrant tersedia dalam paket yangdapat digunakan pada area terbuka atau

jika pengujian sebagian dari benda ujiyang besar

A V i s i b le d y e p e n e t r a n t k i t u s u a l l yc o n t a i n s :

1. Pressurized spray cans of cleaning orremoval fluid.

2. Pressurized spray cans of visible dyepenetrant.

3. Pressurized spray cans of non-

aqueous developer.4. Wiping cloths and brushes.

V i si b le p e n e t r a n t u m u m n y a b e r i s i :

1. Kaleng semprot bertekanan berisicairan pembersih

2. Kaleng semprot bertekanan berisivisible penetrant.

3. Kaleng semprot bertekanan berisi

non-aqueous developer.4. Kain lap dan sikat.

A f l u o r e s c e n t d y e p e n e t r a n t k i t usually contains:1. A portable black light and

transformer2. pressurized spray cans of cleaning or

removal fluid3. Pressurized spray cans of fluorescent

dye penetrant4. Pressurized spray cans of non-

aqueous developer5. wiping cloths and brushes

P a k e t f l u o r e s c e n t p e n e t r a n t umumnya berisi:1. Lampu ultraviolet dengan trafo2. Kaleng semprot bertekanan berisi

cairan pembersih3. Kaleng semprot bertekanan berisi

fluorescent penetrant4. Kaleng semprot bertekanan berisi

non-aqueous developer

5. Kain lap dan sikat

B l ac k l ig h t e q u i p m e n t is required influorescent penetrant testing since itsupplies light of correct wavelength tocause the penetrant to fluoresce.

A deep red-purple filter is used to passonly those wavelengths of light that willactivate the fluorescent material.

At least a five-minute heat-up time isrequired to reach the correct arctemperature when using mercury arclamps.The black light emits a special light withwavelengths that fall between visibleand ultraviolet, provided that the filter isnot broken or cracked.

There is no danger of injury to thehuman eye, it is suggested that the filter

be checked prior to each use.

L am p u u l t r a v i o l e t diperlukan dalampengujian fluorescent penetrant karenamengeluarkan/memancarkan sinardengan panjang gelombang yangsehingga untuk menyebabkan penetrantberpendar. Filter warna ungu-merahgelap digunakan untuk dilalui sinardengan panjang gelombang tertentu,yang akan mengaktipkan material

fluorescent. Sedikitnya diperlukanpemanasan selama 5 menit untukmencapai temperatur yang benar, jikamenggunakan lampu mercury.Black light memancarkan sinar denganpanjang gelombang antara visible danultraviolet, asalkan filter tidak pecahatau retak

Tidak ada bahaya kerusakan pada mata,disarankan filter dicek sebelum

pemakaian Penetrant testing materials can be used Material penetrant dapat digunakan


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in a variety of combinations. Mostmaterials are available in eitherpressurized spray cans or in bulkquantities.The flow chart below illustrates thedifferent material combinations, howevercare should always be taken to assurethat manufacturers specifications orcompany procedures are closelyfollowed.

dengan berbagai kombinasi. Kebanyakanmaterial tersedia dalam kaleng semprotbertekanan atau dalam bak besar(cairan)Diagram alur di bawah menggambarkankombinasi material yang berbeda,bagaimanapun perhatian selalu diambiluntuk meyakinkan bahwa spesifikasipabrikan atau prosedur perusahaandiikuti.

P en e t r a n t t e s t i n g m a t e r i a lsPenetrant materials are often restrictedto specific groups. The establishedgroups of penetrant materials will usethe following in a variety ofcombinations to obtain the best results.1. W a t e r - w a s h a b l e p e n e t r a n t s –

contain an emulsifying agent whichmakes them easily removable by awater rinse or wash. This penetrantmaterial can be obtained with eithera visible or fluorescent dye.

2. P o st - e m u l s if i ab l e p e n e t r a n t s –are highly penetrating. Oily visible orfluorescent penetrant which are notsoluble in water. These penetrants

M a t e r i a l p e n e t r a n tMaterial penetrant dibagi dalamkelompok tertentu. Kelompok materialpenetrant akan menggunakan berbagaikombinasi untuk memperoleh hasil yangterbaik.1. W a t e r - w a sh a b l e p e n e t r a n t –

mengandung pengemulsi yangmembuat penetrant mudahdibersihkan dengan air pembilas ataudicuci. Material penetrant ini dapatdiperoleh dengan visible ataufluorescent

2. P o st - e m u s i f i a b le p e n e t r a n t – dayapenetrasi dalam. Penetrant visibledengan bahan dasar minyak atau


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must be treated with an emulsifierbefore they can be removed by awater rinse or wash.

3. So l v e n t - r e m o v a b l e p e n e t r a n t s –are oily penetrants that do notcontain an emulsifying agent and areremovable only by solvent specificallydesigned for that purpose

4. Em u l s i f ie r s – when applied apenetrants coated specimen makethe resultant mixture removable bywater rinse or wash.Emulsifiers have low penetrantcharacteristics and do not removeindications from the specimensurface.

5. R e m o v e r s (solvent) – are designedto be used in conjunction withspecific penetrants. Typical removersare available in bulk or pressurizedspray containers

6. D r y D e v e l o p e r s – are a fluffy,absorbent white powder that is usedin both fluorescent and visible dyepenetrant tests. It functions to drawthe penetrant indications to thesurface thus making them visible.

7. W e t D e v e lo p e r s – function similarlyto dry developers except that theyare a mixture of a developing powderand water.

8. N o n - a q u e o u s w e t d e v e l o p e r s –differ from wet developers in that

the developer powder is mixed with arapid-drying liquid solvent

9. L iq u i d O x y g e n ( L OX ) c o m p a t i b l em a t e r i a ls – must be used whenarticles inspected are subjected tocontact with either liquid or gaseousoxygen. These materials arespecifically designed to be inert whenin the presence of lox

10. L o w s u l f u r a n d l o w c h lo r i n e –

penetrant materials must bespecifically designed to avoid the

flourecent yang tidak larut dalam air.Penetrant ini harus diberi denganemulsifier sebelum dapat dibersihkandengan air pembilas atau dicuci

3. So l v e n t - r e m o v a b l e p e n e t r a n t - penetrant dengan bahan dasarminyak yang tidak berisi pengemulsidan dapat dibersihkan hanya dengansolvent yang dirancang khusus untukmaksud pembersihan.

4. Em u l s i f ie r s - jika dilapiskan padabenda uji berpenentrant, membuatcampuran yang dapat dibersihkandengan air pembilas atau dicuci.Pengemulsi mempunyai karakteristikpenetrant rendah dan tidakmembersihkan indikasi dalampermukaan benda uji.

5. R e m o v e r (solvent) - dirancanguntuk digunakan bersamaan denganpenetrant tertentu. Pembersih initersedia dalam jumlah besar (cairan)atau dalam kaleng semprotbertekanan.

6. D r y D e v e l o p e r s – bubuk putih haluspenyerap yang digunakan padapengujian penetrant visible danfluorescent. Fungsinya untuk menarikpenetrant ke permukaan sehinggamembuat terlihat (terbaca)

7. We t D e v e l o p e r s – fungsinya samadengan dry developer, merupakancampuran bubuk developer dengan air

8. N o n - a q u e o u s w e t d e v e l o p e r s –berbeda dengan wet developer, dalam

hal ini bubuk developer dicampurdengan cairan pelarut (solvent) cepatkering

9. L iq u i d O x y g e n ( L OX ) c o m p a t i b l em a t e r i a ls – harus digunakan jikabenda uji berhubungan (contact)dengan cairan atau gas oxygen.Material ini dirancang untuk tidakbereaksi ketika ada lox

10. L o w s u l f u r a n d l o w c h lo r i n e –

material penetrant harus dirancanguntuk menghindari efek yang


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harmful effects caused on somenickel and titanium alloys by thesulfur and chlorine content.

berbahaya terhadap campuran nikeldan titanium oleh kandungan belerangdan khlor.

S a f et y p r e c a u t i o n sAn general the materials used inpenetrant inspection can be flammableand can cause skin irritations

An addition, the ultraviolet spectrum oflight rays generated from the mercuryarc lamp can cause sunburn and may beinjurious to the eyes.However. If the proper filter forfluorescent dye inspection is used, theharmful rays will be filtered out.

F i r e – many penetrant materials areflammable. Safe practice requires thatpenetrant materials used in open tankshave a flashpoint pf greater than 120

˚

F

Sk i n I r r i t a t i o n – skin irritation can beavoided by preventing unnecessarycontact and by the use of gloves,aprons, and protective hand creams.

A i r P o l l u t i o n – the developing powdersare considered nontoxic, but excessiveinhalation must be avoided. Exhaustfans should be installed in any confinedarea where dry developers or vaporsfrom the penetrants are present.

T in d a k a n p e n c e g a h a nPada umumnya material yang digunakandalam inspeksi penetrant dapat mudahterbakar dan dapat menyebabkan iritasikulitJuga, spektrum sinar ultravioletditimbulkan dari lampu mercury dapatmenyebabkan kulit terbakar danmungkin berbahaya pada mata.Bagaimanapun, jika filternya benar yangdigunakan untuk inspeksi fluorescent,sinar yang berbahaya akan dihilangkan.K e b a k a r a n – kebanyakan materialpenetrant mudah terbakar. Praktek yangaman memerlukan bahwa materialpenetrant digunakan dalam tangkiterbuka mempunyai titik bakar lebihbesar dari 120

˚

FI r i t a s i K u l i t – iritasi kulit dapat dihindaridengan mencegah kontak yang tidakperlu dan menggunaan sarung tangan,celemek, dan krim pelindung tanganP o l u s i U d a r a – bubuk developer tidakberacun, tetapi menghirup berlebihanharus dihindarkan. Kipas penghisapudara dipasang pada area tertutupdimana ada bubuk developer atau uappenetrant.


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Quiz 2

_____ 1. Wire brushing is a common and acceptable method of surface cleaning atest part that is to be penetrant inspected.

_____ 2. A good exhaust system is recommended when working with cleaningsolvents.

_____ 3. Vapor degresing is often used to remove oxidation, rust and scale beforea part is penetant inspected.

_____ 4. Parts that have been painted usually cannot be inspected with penetrantsbecause suitable paint removing techniques have not been developed.

_____ 5. Detergent cleaning is acceptable for postcleaning but should neveer beused for precleaning because it may affect the emulsifier during the thepenetrant test.

_____ 6. Etching is often effective in precleaning a part that has been machined toa specific tolerance by surface ginding.

_____ 7. Only visible dye penetants are available in portable kits becausefluorescent dyes will not function in pressurized spray cans.

_____ 8. Dry developers are usually only used with visible dye penetrants. _____ 9. Emulsifiers and solvents are both commonly used in penetrant testing as

postcleaners. _____ 10. Wet developers should never be used when they will come into contact

with gaseous or liquid oxygen because of the results caused by oxygenand water mixing.

_____ 11. Emulsifiers must have high penetrating characterstics to emulsifypenetrants that lie in fillets and cornes.

_____ 12. The black light used in fluorescent penetrant inspection is not hazardousto the human eyes if the correct filter is in place and not broken orcracked.

_____ 13. Penetrant materials are often placed in groupings that will assure a validtest with materials that ae compatible with each other.

_____ 14. Nonaqueous developer refers to a powder that is applied dry. _____ 15. Post-emulsifiable penetrants are usually soluble in water after the

application of an emulsifier. _____ 16. Water-washable penetrants are commonly used with either a visible or

fluorescent dye.

_____ 17. Flashpoint refers to the lowest temperature at which vapors will ignitewhen exposed to flame.


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LESSON – 3

This lesson discusses surfacepreparation and penetrant application Pelajaran ini mendiskusikan persiapanpermukaan dan aplikasi penetrant

C l e a n i n gThe effectiveness of liquid penetranttesting is based upon the ability of thepenetrant to enter surfacediscontinuities. All paint, carbon, oil,varnish, oxide, plating, water, dirt, andsimilar coating must be removed beforeapplication of the penetrant.Liquid penetrant placed on the surface ofa specimen does not merely seep intodiscontinuities. It is pulled into them bycapillary action this is reason one cancover the under surface of an item witha penetrant and still have a valid test.

P em b e r s ih a nEfektivitas pengujian cairan penetrantdidasarkan pada kemampuan penetrantuntuk masuk ke dalam cacat permukaan.Semua cat, karbon, minyak, pernis,oksida, lapisan, air, kotoran, dan lapisansejenis harus dibersihkan sebelumaplikasi penetrant.Cairan penetrant pada permukaanbenda uji tidak merembes ke dalamcacat. Penetrant ditarik ke dalam cacatdengan tindakan kapiler (capillaryaction), ini satu alasan dapatmengungkap penetrant di bawahpermukaan benda uji dan pengujianmasih dipercaya


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The following are typical cleaningmethods discussed earlier.1. Detergent cleaning2. Vapor degreasing3. Steam cleaning4. Ultrasonic cleaning5. Rust and surface scale removal

6. Paint removal7. Etching

Berikut adalah jenis metodapembersihan yang telah dibahas di awal.

1. Pembersihan dengan detergent2. Pembersihan dengan penguapan3. Pembersihan dengan uap4. Pembersihan dengan ultrasonic5. Pembersihan karat dan kerak

permukaan.6. Pembersihan cat7. Pengetsaan

A p p l i ca t i o n o f p e n e t r a n t sAlmost any liquid could be considered apenetrant, but modern penetrants must

have1. The ability to hold a dye material insuspension

2. The ability to spread the dye evenlyover the surface

3. The ability to carry the dye into anydiscontinuity open the surface

4. The ability to bring up the dye as it iscoaxed back to the surface

5. The ability when desired to be easilyremoved

A p l ik a s i p e n e t r a n tHampir setiap cairan disebut penetrant,tetapi penetrant modern harus

mempunyai1. Kemampuan untuk menahan material(warna) dalam suspensi

2. Kemampuan untuk menyebar cairandi atas permukaan

3. Kemampuan untuk membawa cairanke dalam setiap cacat permukaanyang terbuka

4. Kemampuan untuk membawa naikcairan kembali ke permukaan

5. Kemampuan ketika diinginkan mudahdihilangkan

There are two types of dye used inmodern penetrants1. Vi s i b l e – a brightly colored dye that

is highly visible under normal lightingconditions. This type of dye isnormally called visible dye

2. F l u o r e s c e n t – an almost colorlessdye which emits visible light rayswhen reviewed under black light

A dye with dual sensitivity contains botha visible dye for examination in whitelight and a fluorescent dye for a moresensitive evaluation of smalldiscontinuities

Ada dua jenis cairan digunakan dalampenetrant modern1. Vi s i b l e – cairan berwarna terang

yang mudah kelihatan di bawahkondisi penerangan normal. Cairan

jenis ini disebut visible dye2. F l u o r e s c e n t – umumnya cairan

tanpa warna yang memancarkansinar cahaya (terlihat), ketika dilihatdi bawah lampu ultraviolet

Cairan dengan dua sensitivitas berisivisible dye (terlihat) untuk pengujian dicahaya normal dan fluorescent dye(berpendar) untuk evaluasi yang lebihsensitip pada cacat kecil

Penetrants either fluorescent or visiblecan be applied by any one of thefollowing means1. S p r a y i n g – usually using a low

pressure circulation pumps or frompressurized spray cans.

2. B r u s h i n g – usually applied with

Penetrant baik fluorescent atau visibledapat diaplikasikan dengan salah satuberikut:

1. S p r a y i n g – umumnya menggunakansirkulasi pompa tekanan rendah ataudari kaleng semprot bertekanan.

2. B r u s h i n g – umumnya dengan kain


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rags, cotton waste. or brushes3. I m m e r s i o n – the entire part is

dipped into a tank of penetrant4. P o u r i n g – the penetrant is simply

poured over the surface

lap, katun atau kuas3. I m m e r s i o n – seluruh bagian dicelup

dalam tangki penetrant4. P o u r i n g – penetrant dituangkan di

atas permukaan

P en e t r a t i o n ( d w e l l ) t i m eThe period of time during which thepenetrant is permitted to remain on thespecimen is a vital part of the testTight crack-like discontinuities mayrequire in excess of 30 minutes forpenetration that will give an adequateindication. However. gross

discontinuities may be suitablypenetrated in 3 to 5 minutesThe temperature of the specimen andtemperature of the penetrant can affectthe required dwell timeWarming the specimen to 70

˚

F or higheraccelerates penetration and shortensdwell time.However, care should be taken not tooverheat the specimen since too muchheat may cause evaporation of thepenetrant from the discontinuityDwell times are based on theassumption that the penetrant willremain wet on the part surface,additional penetrant may be appliedduring dwell timeThe penetrant manufacturer will providesuggested dwell times for the variouspenetrants that it produces.

W a k t u P e n e t r a s iPeriode waktu selama penetrantdibiarkan untuk tinggal pada benda ujiadalah bagian penting pengujianCacat retak halus bisa memerlukan lebihdari 30 menit untuk penetrasi yang akanmemberi indikasi yang cukup. Tetapi,cacat yang besar dipenetrasi dalam 3

sampai 5 menitTemperatur benda uji dan temperaturpenetrant dapat mempengaruhi waktu(dwell) yang diperlukanBenda uji 70

˚

F atau lebih, mempercepatpenetrasi dan memendekkan dwell time.

Bagaimanapun, perhatian diperlukanuntuk tidak panas berlebih pada bendauji, terlalu panas dapat menyebabkanpenguapan penetrant dalam cacatDwell time didasarkan pada asumsibahwa penetrant akan tetap basah padapermukaan, tambahan penetrant bolehdiaplikasikan selama dwell timePabrikan penetrant akan memberikansaran dwell time untuk berbagaipenetrant yang diproduksi

P e n e t r a n t t e s t i n g p r o c e s s e sWe previously mentioned the two typesof penetrants visible and fluorescent. Forboth categories there is a furtherbreakdown.1. W a t e r - w a s h a b l e (visible or

fluorescent)2. P o s t - e m u l s i f ic a t i o n (visible or

fluorescent)3. So l v e n t - r e m o v a b l e (visible or

fluorescent)

P r o se s p e n g u j i a n p e n e t r a n tKita sebelumnya menyebutkan dua jenispenetrant visible dan fluorescent. Untukkedua kategori ada uraian lebih lanjut

1. W a t e r - w a sh a b l e (visible ataufluorescent)

2. P o s t - e m u l s i f ic a t i o n (visible ataufluorescent)

3. So l v e n t - r e m o v a b l e (visible ataufluorescent


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So l v e n t - r e m o v a b l e p e n e t r a n t s – theyhave the advantage of portability andcan be used outdoors without usingheavy, complex equipment.

They are excellent for manymaintenance inspections and forchecking portions of a larger structure.Penetrant is often applied from apressurized spray can which makes thesystem very portable.After the specified dwell time, the excesspenetrant is first removed by wiping withabsorbent towels and then cleaned withtowels dampened with solvent.

Solvent is never applied directly to thespecimen as it might wash out or dilutethe penetrant in the discontinuity.

(see page 20 for advantages anddisadvantages of solvent-removablepenetrants)

So l v e n t r e m o v a b l e p e n e t r a n t s –mempunyai keuntungan dari portabilitasdan dapat digunakan di luar ruangantanpa menggunakan peralatan yang

berat dan kompleksSangat sempurna untuk inspeksipemeliharaan dan untuk mengecekbagian suatu konstrulsi besar.Penetrant diaplikasikan dari kalengsemprot bertekanan yang membuatsistem sangat portableSetelah dwell time yang ditetapkan,kelebihan penetrant, pertamadibersihkan dengan menyeka denganhanduk penyerap dan kemudian

dibersihkan dengan handuk yangdibasahi dengan solvent.Solvent tidak diaplikasikan secaralangsung ke benda uji yang mungkinmembersihkan atau mengencerkanpenetrant dalam cacat(lihat halaman 20 untuk keuntungan dankerugian-kerugian dari solvent-removable penetrants)

Post-emulsification penetrants require atwo-step removal process. Theemulsifier is usually applied by dippingor immersion. The amount of dwell timein the emulsifier is in the range of one tofour minutes in accordance with

Post-emulsification penetrantmemerlukan dua langkah pembersihan.Emulsifier umumnya diaplikasikandengan mencelupkan atau direndam.Dwell time dalam emulsifier sekitar satusampai empat menit berdasarkan


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3. POST-EMULSIFICATION 3. POST-EMULSIFICATION Advantages Keuntungan

High sensitivity for very finediscontinuitiesGood on wide shallow discontinuitiesEasily washed with water afteremulsificationShort penetration timeCannot be easily over washed

Sensitifitas tinggi untuk cacat sangatkecilBaik untuk cacat lebar dan dangkalMudah dicuci dengan air setelahemulsifisikasiWaktu penetrasi pendekTidak mudah dicuci berlebih

Disadvantages KerugianTwo step processEquipment required for emulsifierapplication

Difficult to remove penetrant fromthreads, keyways, blind holes andrough-surfaces

Dua langkah prosesPeralatan diperlukan untuk aplikasiemulsifier

Sulit membersihkan penetrant dari ulir,keyways, lubang dan permukaan kasar

L ea k - t h r o u g h t e c h n i q u e – the use ofliquid penetrant in this method is suitedfor finding leaks in such articles astanks, piping, tubing, and hollowcastings. The sketch below illustrates theleak-through technique.

L e a k - t h r o u g h t e c h n i q u e –menggunaan cairan penetrant dalammetoda ini, cocok untuk mencarikebocoran pada artikel seperti tangki,pipa, tubing dan pipa cor. Sket di bawahmenggambarkan leak-through teknik

Fi x i n g a n d r e c o r d i n g i n d i c a t i o n s1. P h o t o g r a p h s – typical black and

white and color film are used with theself-developing films providing themost convenience.

2. S p e ci a l w a x a n d p l a s t i c f i l md e v e l o p e r s – have beendeveloped to absorb and fix thepenetrant indication to form apermanent record :

A. S t r i p p a b l e l a cq u e r s are sprayed inseveral coats over the indication andwhen dry can be “lifted” to provide apermanent record.

B. S p e c i a l “ f i x e r s ” are sprayed overthe indication and when dry are liftedwith transparent tape.

R ek a m a n i n d i k a s i1. P h o t o – jenis photo hitam putih dan

warna digunakan dengan self-developing film, lebih sesuai

2. L il in k h u s u s d a n p l a s t i k f i l md e v e l o p e r – telah dikembangkanuntuk menyerap dan menentukanindikasi penetrant ke bentukrekaman permanen.

A. P e r n i s s t r i p p a b l e disemprotkanpada indikasi dan setelah keringdapat " diangkat" untuk rekamanpermanen.

B. F i x e r k h u s u s disemprotkan padaindikasi dan setelah kering diangkatdengan isolasi transparan.


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Quiz 3

______ 1. A dual sensitivity penetrant contains a special dye that is visible inwhile light and will fluorsce without the use of a black light.

______ 2. A part eing penetrant inspected must stay immersedin the penetranttank for the entire specified dwell time.

______ 3. The liquid penetrant leak-through test eers to the ability of penetrant tospread through the dry developer evenly.

______ 4. Visible dye penterants are usually considered o be less sensitive thanfluorescent penetrants.

______ 5. Water-washable pnetrants have built-in emulsifier that permits goodresults in penetrant rremoval from parts suspected of having wide orshallow discontinuitis.

______ 6. Solvent-removable penetrants are available in both visible andfluorescent dye.

______ 7. Excess post-emulsifiable penetrant is commonly removed bay sprayingthe surface of the part with cleaner (solvent) and then wiping with alint-free towel.

______ 8. Water-washable penetrant systems arre usualy very portable becausethe mateials are commonly used in pressurized spray cans.

______ 9. Warming the specimen to tempetaues up to about 70 0F tendsaccelerate penetration and shortens dwell time.

______ 10. For the dwell tim to e accurate, the surface of the specimen must stayet with penetrant for entire time specified.

______ 11. The typical dwell time for most penetrant inspections is about 20 – 30minutes.

______ 12. List two (2) of the commonly used methods of applying penetrant tothe specimen is to be inspected.

______ 13. List four of he commonly used methods of precleaning the specimenbefore penetrant inspection.

______ 14. If you were asked to examine 200 steel bolts, each ¾ x 3 inches withrolled threads, which penetrant method would you choose?(a) post-emulsification (b) water-washable


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Lesson – 4

This lesson discusses emulsification,penetrant removal, and developerapplication.

Pelajaran ini mendiskusikan emulsifikasi,pembersihan penetrant, dan aplikasideveloper

P o s t – e m u l s i f ic a t i o n p e n e t r a n t (P.E.Penetrant)This type of penetrant emulsification isaccomplished by dipping the part in achemical emulsifier prior to washing. Theemulsifier will break down the penetrantand make it water soluble.The emulsifier can be applied by dippingor spraying, but not by brushing. Thebristles of the brush may enter thediscontinuity.

P o s t - Em u l s i f ic a t i o n Pe n e t r a n t (P.E.Penetrant)Emulsifikasi penetrant jenis inidikerjakan dengan mencelupkan bendauji dalam chemikal emulsifier sebelumdicuci. Emulsifier akan membuatpenetrant dapat larut dalam air.Emulsifier dapat diaplikasikan denganpencelupan atau peyemprotan, tetapitidak dengan kuas (bristle). Bulu kuasdapat masuk dalam cacat.


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The sketch below represents the steps ina post-emulsification penetrant test.

Sket di bawah menggambakan langkah-langkah dalam pengujian post-emulsification penetrant

If too short an emulsification time isused, not all penetrant will be removed,which will cloud over discontinuities.

If too long a time is used, penetrantwithin the discontinuities will alsobecome water soluble and be washed

away with excess penetrant.The P.E.Penetrant makes the water wash

Jika terlalu pendek waktu emulsifikasiyang digunakan, tidak semua penetrantakan dibersihkan, yang akan menutupicacat.Jika terlalu lama waktu yang digunakan,penetrant di dalam cacat akan menjadilarut dalam air dan dihanyutkan dengan

kelebihan penetrant.P.E.Penetrant membuat pencucian


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less critical.

The sketches below compare the effectsof water-washable and post-emulsificatinpenetrants.

dengan air lebih kritis.

Sket di bawah membandingkan efekwater-washable dan post-emulsificatinpenetrants.

D e v e l o p e r a p p l i c a t i o nSome indications may be visible prior tothe application of a developer but thisstep will ensure that all discontinuities

are visible to the naked eye.

Developing is accomplished when ahighly absorbent powder is applied tothe item being tested after excesspenetrant is removed.

The penetrant is actually drawn out ofthe discontinuity by the strong capillaryaction of the developer.

A p l i k a s i d e v e l o p e rBeberapa indikasi (cacat) mungkinkelihatan sebelum aplikasi developertetapi langkah ini akan memastikan

bahwa semua cacat kelihatan oleh matabiasa.Developing terjadi ketika bedak (serbuk)penyerap diaplikasikan pada item yangakan diuji setelah kelebihan penetrantdibersihkan.

Penetrant ditarik keluar dari cacatdengan tindakan kapiler yang kuat(capillary action) dari developer.


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As shown above, the image of thediscontinuity in the developer will

actually be larger than the actual size ofthe discontinuity.

Ditunjukkan di atas, gambar cacat didalam developer akan menjadi lebih

besar dari ukuran cacat yang sebenarnya

There are two common types ofdevelopers in use today – w e t and d r y ,both use a white powder and theprimary difference is in the method ofapplication.1 . W e t d e v e l o p e r sA. The n o n a q u e o u s developer is held

in suspension in a solvent base and isusually supplied in pressurized cans.

B. Another type of wet developer holds the white powder in suspensionin a water base.

This type of wet developer is generallyused with water-washable orP.E.Penetrants and is applied by dippingor spraying. After application, a shorttime is allowed for the water toevaporate leaving a thin layer of whitepowder. If an oven is used, thetemperature should not exceed about225

˚ F as this could evaporate penetrantin the disconituity.

Ada dua jenis developer saat ini – b a s a h dan k e r i n g , dan kering, keduanyamenggunakan bedak putih danperbedaan yang utama adalah di dalammetoda aplikasinya1 . W e t d e v e lo p e r ( b a sa h )A. Developer n o n a q u e o u s dibuat

campuran dengan solvent danumumnya disediakan dalam kalengbertekanan

B. Jenis lain wet developer dibuatcampuran bedak putih dengan air

Jenis wet developer ini, biasanyadigunakan dengan water-washable atauP.E.Penetrants dan diaplikasikan denganpencelupan atau penyemprotan. Setelahaplikasi, waktu yang singkat diberikanuntuk air menguap menyisakan lapisantipis bedak putih. Jika pemanasdigunakan, temperatur tidak melebihi225

˚

F hal ini dapat menguapkanpenetrant di dalam cacat.

2 . D r y d e v e l o p e r sA dry developer is a fluffy white powderthat is not carried in a liquid.

Dry developers are applied directly tothe article as a powder. This is usuallydone with slight air pressure or articlesmay be dipped into a container of drydeveloper.

2 . D r y d e v e l o p e r ( k e r i n g )Developer kering adalah bedak putihhalus yang tidak dicampur cairan.

Developer kering diaplikasikan secaralangsung ke artikel. Pada umumnyadilakukan dengan tekanan udara rendahatau dicelupkan dalam wadah developerkering


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It is very necessary to have a drysurface prior to application of a drypowder. A wet surface will result inuneven layers of powder.Dry developer is usually used onfluorescent penetrants.

Sangat penting permukaan harus keringsebelum aplikasi developer kering.Permukaan basah akan mengakibatkanlapisan bedak tidak merataDeveloper kering pada umumnyadigunakan pada fluorescent penetrants.

A d v a n t a g e s o f “ W e t ” d e v e l o p e r sBetter on smooth surfaces where the drydeveloper will not adhere.

When a wide, shallow discontinuity issought, a wet developer will leave amore even coat of developer.

K e u n t u n g a n " D e v e lo p e r b a s ah ”Sangat baik pada permukaan halusdimana developer kering tidak akanmelekat.Jika cacat yang lebar dan dangkal dicari,developer basah akan menghasilkanlapisan developer yang merata

A d v a n t a g e s o f “ d r y ” d e v e l o p e r sOn rough surfaces, and on sharp fillets,holes, and threaded articles, the wetdeveloper tends to leave too muchdeveloper.

K e u n t u n g a n " D e v e l o p er k e r i n g "Pada permukaan kasar, sudut yangtajam, lubang, artikel berulir, developerbasah cenderung meninggalkan banyakdeveloper


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Quiz 4

______ 1. When using a post-emulsified penetrant, if too long a time is used foremulsification, penetrant within the discontinuities will be washed awaywith the excess penetrant

______ 2. During the rinse cycle, an emulsifier is added to a solvent-removeablepenetrant to make it water soluble

______ 3. Water-washable penetrants have a bulit-in emulsifier ______ 4. Post-emulsification penetrants are commonly available in both visible

and fluorescent dyes ______ 5. Post-emulsification penetrants usually require a two-step penetrant

removal process ______ 6. The penetrant removal process with water-washable penetrants is very

critical because of the danger of over-wash ______ 7. Solvent-removable penetrants are commonly used because they will

wihstand a very forceful water wash without the danger of aver-wash ______ 8. An advantage of the solvent-removable penetrant is that th excess

penetrant is easily removed by dipping the part in a tank of solventsolution

______ 9. Wet developers are usually chosen over a dry developer for use on asmooth surface

______ 10. A major advantage of the dry devloper over is that it will not leave thesame amount of excess build-up in threads and fillets

______ 11. The emulsification time required to detect wide or shallow discontinuitesis usually longer than for finding narrow and deep discontinuities

______ 12. To avoid over-wash when using water-washable penetrants the waterrspray nozlle is usually held at a 90 0 angle to the surface

______ 13. When using a water-washable penetrant, the part must be completelydried in an oven (not in excess of 225 0F) before th wet developer can beapplied

______ 14. A major advantage of a nonaqueous developer is that it can be appliedto a part is heated above 225 0F wihout evaporation on the developervehicle

______ 15. Solvent-removable fluorecent penetrants require the use of a rather timeconsumming method of excess penetrant removal

______ 16. Post-emulsified visible dye penetrants commonly use both wet and dry

developers


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Lesson – 5

This lesson discusses the final steps inthe penetrant process inspection,evaluation, post-cleaning, and materialcontrol.

Pelajaran ini mendiskusikan langkah-langkah akhir di dalam proses inspeksipenetrant, evaluasi, pembersihan akhir,dan pengendalian material.

I n s p e c t io nProper lighting should be the firstconsideration in the inspection of anarticle.1. If a fluorescent dye penetrant is

used, a room or booth with dim lightand a black light with proper intensityare required.

2. If a visible dye penetrant is used,adequate normal lighting isnecessary.

I n s p e k s iPencahayaan yang cukup harusmerupakan pertimbangan yang pertamadi dalam inspeksi artikel (barang)1. Jika penetrant fluorescent digunakan,

ruangan gelap dan lampu ultravioletdengan intensitas yang sesuaidiperlukan.

2. Jika penetrant visible digunakan,pencahayaan normal yang cukupadalah perlu.

Ty p i c a l i n d i c a t i o n s i n p e n e t r a n ti n s p e c t i o nAll indications found with the liquidpenetrant method will be surfacediscontinuities, but the indications mayor may not affect the usefulness of thearticle.

Je n i s i n d i k a s i d i d a l a m i n s p e k s ip e n e t r a n tSemua indikasi yang ditemukan denganmetoda penetrant metoda adalah cacatpermukaan, tetapi indikasi - indikasidapat atau tidak dapat mempengaruhikegunaan artikel (barang)

F a ls e in d i c a t i o n sThe most common source of falseindication is poor washing.The operator can easily tell when a goodrinse is obtained by using a black lightduring and after the fluorescentpenetrant removal process.

To avoid f a l s e i n d i c a t i o n s , care shouldbe taken so that no outside

contamination such as the followingoccurs.

I n d i k a s i p a ls uSumber yang umum indikasi palsuadalah pembersihan yang kurang baik.Operator dapat memberitahukan jikapembilasan yang baik dicapai denganmenggunakan lampu ultraviolet selamadan setelah proses pembersihanpenetrant fluorescent

Untuk menghindari i n d i k a s i p a l s u ,perhatian harus diambil sehingga tidak

ada pencemaran dari luar seperti yangberikut terjadi.


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1. Penetrant on operator’s hands2. Contamination of developer3. Contamination transferred to clean

specimen from other indication.4. Penetrant on inspection table

1. Penetrant ditangan operator2. Pencemaran developer3. Pencemaran yang ditransfer ke

spesimen bersih dari indikasi lainnya4. Penetrant pada meja inspeksi

N o n - r e l ev e n t i n d i ca t i o n sNon-relevent indications are actualsurface discontinuities that in most casesare there by design.They are caused by some feature ofassembly such as articles that arepressfitted, keyed, splined, or riveted.Non- relevant indications could alsoinclude loose scale or a rough surface ona forging or casting.

I n d i k a s i n o n - r e l e v a n tIndikasi non-relevant adalah cacatpermukaan nyata yang dalam banyakkasus adalah karena perencanaan. Itudisebabkan oleh beberapa cara perakitanseperti artikel yang disambung dengantekanan, disetem, splined, atau dikeling.Indiksi non-relevant dapat juga termasukkerak yang lepas atau permukaan kasarpada tempaan atau tuangan (cor)

T r u e I n d i c a t io n s(some typical indications are shown inchapter 6, pages 8-19 in the traininghandbook)True indications are those caused bysurface discontinuities that have been

interpreted as not being false or non-relevant.True indications are subject to evalution

I n d i k a s i a s l i(beberapa jenis indikasi ditunjukkan dibab 6, halaman 8-19 dalam traininghand book)Indikasi asli adalah yang disebabkan olehcacat permukaan yang telah

diinterprestasi tidak palsu atau non-relevant.Indikasi asli harus dievaluasi bisa jadi


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as to the cause and the effect they eillhave on the service life of the article.

True indications could be divided intofive basic categories:1. Continuous line- this type of

indication is often caused by cracks,cold shuts, forging laps, scratches,or die marks.

2. Intermittent line- these indicationscould be caused by any of the3discontinuities mentioned aboveprovided they were very tight orwhere the part had been peened,machined, or ground.

3. Round –usually caused by porosityopen to the surface.

4. Small dots- tiny round indicationscaused by the porous nature of thespecimen, coarse grain structure, ormicroshrinkage.

Diffused or weak – these indications aredifficult to interpret and often the partmust be cleaned and retested. In maycases the diffused or weak indicationsturn out to be false indications causedby an improper penetrant procedure.

penyebab dan dampaknya terhadapumur operasi dari artikel (barang).

Indikasi asli dapat dibagi menjadi limakategori dasar:1. Garis tidak terputus- jenis indikasi ini

sering disebabkan oleh retak, celah,lapisan tempaan, goresan, ataubekas press.

2. Garis terputus putus – indikasi inidapat disebabkan oleh cacat tersebutdi atas, tetapi sangat rapat atautelah dipukuli, dimachining ataudiratakan.

3. Bulat – umumnya disebabkan olehporositas permukaan yang terbuka.

4. Titik kecil-kecil – indikasi bulat kecildisebabkan oleh porositas alami darispecimen, struktur butiran kasar,atau microshrinkage.

5. Samar – indikasi ini sulit untukdiinterpretasi dan sering benda ujiharus dibersihkan dan diuji kembali.Dalam banyak hal indikasi samaradalah indikasi palsu disebabkan olehprosedur penetrant yang tidaksesuai.

D e p t h d e t e r m i n a t i o n o f p e n e t r a n td i s c o n t i n u i t i e sThe greater the depth of a discontinuity,the more penetrant it will hold and thelarger and brighter the indication.

P en e n t u a n k e a d a l a m a n c a ca tp e n e t r a n tSemakin besar kedalaman cacat,semakin banyak penetrant di dalamnyadan lebih besar dan lebih terangindikasinya.

P o s t - c l ea n i n g

After the specimen has been inspected itis very important that it be thoroughlycleaned. Post-cleaning usually willinvolve the same types of cleaningoperations as were used in pre-cleaning.

P em b e r s ih a n a k h i r

Setelah specimen diinspeksi, sangatpenting untuk dibersihkan. Pembersihanakhir pada umumnya sama denganoperasi pembersihan yang digunakanpada pre-cleaning.

Q u a l i t y c o n t r o l o f p e n e t r a n t t e s tm a t e r i a lsA l u m i n u m t e s t b l o c k s – they providea good means of evaluating generalpurpose penetrants.They should be used for comparisons

only and not for absolute evaluations.

P en g e n d a l i a n m u t u m a t e r i a lp e n g u j i an p e n e t r a n tBlok alumunium – alat yang baik untukmengevaluasi penetrant secara umum.

Blok harus digunakan untuk

membandingkan saja dan bukan untukevaluasi absolute.


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These blocks are non-uniform, and thedepth and width of cracks areuncontrolled.The size of the blocks may vary but areabout 3/8 by 2 inches of 2024-T-3Aluminum about 3 inches long.The blocks are heated and quenched toproduce an overall crack pattern. Theycan be reused by reheating, quenching,and careful cleaning.

Blok ini tidak uniform, dan kedalamandan lebar retak tidak dikendalikan.

Ukuran blok bervariasi tetapi antara 3/8x 2 inchi dari Aluminium 2024-T-3panjang 3 inchi.Blok dipanaskan (quenching) untukmembuat retak. Blok dapat digunakankembali dengan pemanasan ulang(quenching), dan pembersihan.

S e n s i t i v i t y t e s t s – while there havebeen no simple quantitative testsdeveloped for measuring penetrantsensitivity. A simple comparative test isusually adequate.

A small sample of penetrant from thetesting area is placed on one side of analuminum test block, and a small sampleof new penetrant on the other side. Byvisual observation it is determined if the

old penetrant is contaminated to thepoint where it must be discarded.

U j i s e n s i t i v i t a s – sementara tidak adauji kwantitatif sederhana yangdikembangkan untuk mengukursensitivitas penetrant. Uji perbandingansederhana pada umumnya cukup.

Contoh sedikit penetrant dari areapengujian ditempatkan pada satu sisiblok alumunium, dan contoh sedikitpenetrant baru di sisi lain. Denganpengamatan visual, ditentukan penetrant

lama tercemar pada tingkat dimanaharus dibuang.

M e n i s c u s t e s t – provides a practicaltest for evaluating the dye concentrationin thin-liquid films.The test utilizes a flat glass platen and aconvex lens. When a drop of solution isplaced between the lens and platen, acolorless or non-fluorescent spot isformed around the point of contact. Theresultant contact angel simply indicatesthe ability of the liquid to wet a surface.The diameter of the remaining “spot” of

U j i M e n i s k u s – menyediakan uji praktisuntuk mengevaluasi konsentrasi cairan didalam lapisan tipis.Uji menggunakan kaca dan lensa-cembung. Ketika setetes cairanditempatkan antara lensa dan kaca, titiktanpa warna atau non-fluorescentdibentuk di sekitar titik kontak. Resultansudut kontak menandai kemampuancairan membasahi permukaan.Sisa diameter titik penetrant tanpa


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colorless penetrant provides a measureof film thickness which can be used tocompare the dye concentration ofpenetrants.Prolonged exposure of a film toultraviolet light or accidentalcontaminations by acids or alkalis willaffect the dye concentration andtherefore change the spot diameter.

warna menyediakan ukuran ketebalanlapisan yang dapat digunakan untukmembandingkan konsentrasi penetrant.

Lama penyinaran dengan sinarultraviolet atau pencemaran oleh acidatau alkali akan mempengaruhikonsentrasi cairan dan oleh karenanyamerubah diameter titik.

Ce r a m i c b lo c k t e s t – consist of anunglazed ceramic disc which hasthousands of micro pores and cracks onits surface.A pencil mark is made on the block anda small amount of a test penetrant isplaced on one side and a referencepenetrant is applied to the other side.

After the correct dwell time. The twopenetrants are compared in a side-by-side visual examination.A reduction in the number or apparentbrightness of pore indications should beobserved when comparing a fresh andold batch of penetrant.

U j i b l o k k e r a m i k – terdiri dari piringkeramik tanpa lapisan cat yangmempunyai beribu-ribu pori-pori mikrodan retak permukaanTanda pensil dibuat pada blok dan sedikitcontoh penetrant ditempatkan pada satusisi dan penetrant acuan diaplikasikanpada sisi lain.

Setelah dwell time cukup. Dua penetrantdibandingkan secara visual satu sisi kesatu sisi lainnyaPengurangan kecerahan pada indikasipori-pori harus diamati ketikamembandingkan penetrant baru danlama

W a t e r c o n t e n t t e s t – the ASTMstandard D-95 describes a test where100 ml of penetrant is placed in a boilingflask with a similar quantity of moisture-free xylene. The condensate is collectedin a graduated tube to show percent ofwater by volume.If percent of water exceedsmanufacturers recommendations, thepenetrant is discarded.

U j i k a n d u n g a n a i r – standar ASTM D-95 menjelaskan dimana 100 mlpenetrant ditempatkan dalam guci didihdengan jumlah yang sama dari moisture-free xylene. Air kondensasi dikumpulkandalam tabung untuk menunjukkanpersentasi air dengan volume.Jika persentasi air melebihi rekomendasipabrikan, penetrant dibuang.

Vi s c o s i t y t e s t – a viscometer tube isused to measure the viscosity incentistokes to determine if the penetrantis within the range recommended by themanufacturer. A typical standard is

Uji kekentalan – tabung viscometerdigunakan untuk mengukur kekentalandalam centistokes untuk menentukan

jika penetrant dalam rentang yangdirekomendasi oleh pabrikan. Standar


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ASTM D-445. adalah ASTM D-445.F l u o r e s c e n t p e n e t r a n t f a d e t e s t –

this test involves the use of thealuminum test blocks in a side by sidecomparison test.The fluorescent penetrant is placed onboth sides of the block and processednormally. One half of the block is thenexposed to a standard black light for onehour. While the other side is coveredwith paper.The fluorescent brilliance of the twosides is observed and, if one side is

noticeably less brilliant, the penetrant isdiscarded.

U j i k e p u d a r a n p e n e t r a n t f l u o r e sc en t

– uji ini menggunakan blok aluminiumdalam uji perbandingan satu sisi ke sisilainPenetrant fluorescent ditempatkan padadua sisi blok dan diproses secara normal.Separuh blok kemudian disinari cahayaultraviolet untuk satu jam. Sementarasisi lain ditutup kertas.

Kecerahan fluorescent dari dua sisidiamati dan, jika satu sisi kelihatan

kurang cerah, penetrant dibuang.

W a t e r w a sh a b i li t y t e s t – this testevaluates the efficiency of the emulsifierby comparing two different percentageblends of penetrant and emulsifier.

A special steel block is placed at a 75˚

and the two blends are allowed to flowseparately down the block. After five

minute waiting period, the block iswashed and examined for traces ofremaining penetrant

U j i k e m a m p u a n c u c i d e n g a n a i r – ujiini mengevaluasi efisiensi emulsifierdengan membandingkan dua campuranpersentase penetrant berbeda danemulsifier.

Blok baja khusus ditempatkan pada 75°dan dua campuran dialirkan secaraterpisah ke blok. Setelah lima menit,

blok dicuci dan diuji untuk sisa penetrant

D e v e l o p e r s – dry developers are simplyvisually inspected to see that they arenot lumpy or caked instead of fluffy andlight.

D e v e l o p e r – developer kering (dry)hanya diinspeksi secara visual untukmelihat bahwa tidak bergumpal merubahhalus dan ringan.

W e t d e v e l o p e r s are often checkedusing a hydrometer to assure that thedensity of the powder in the vehicle iswithin the range recommended by themanufacturer.

Developer basah (wet) – sering dicekmenggunakan hidrometer untukmeyakinkan bahwa density bedak dalamcairan masih dalam rentang yangdirekomendasikan oleh pabrikan.

Fi l t e r e d p a r t i c l e m e t h o d o fp e n e t r a n t i n s p e ct i o n – when testing aporous surface with filtered particles, theincreased area created by a crack will

“filter” the penetrant, leaving theparticles on the surface.

M e t o d a p e n y a r i n g a n p a r t i k e l p a d ai n s p e k s i p e n e t r a n t – jika pengujianpermukaan berpori-pori dengan saringanpartikel, penambahan area yangdibentuk oleh retak akan " menyaring "penetrant, meninggalkan partikel padapermukaan


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Quiz 5

______ 1. A typical false indication could be caused by an assembly that requires thecomponents to be press-fitted

______ 2. Nonrelevant indications could be caused by rough surface on casting ______ 3. Postcleaning is necessary only when the part must be retested by the

liquid penetrant method ______ 4. A typical true indication producing round indications is commonly caused

by porosity ______ 5. Diffused or weak indications are often caused by subsurface

discontionuites, and the part must be retested using a highly sensitivepenetant that will penetrae grain structure

______ 6. True indications are usually those that require evaluation to determinetheir effect on the service life of the part

______ 7. The aluminium test block used in penetrant evaluaion are heated andquenched in water to produce a pattern of cracks on the surface

______ 8. The sensitivity tests used in penetrant inspection ae relatively simple,nonquaniative, and rrequie side-by-side visual observaion

______ 9. The meniscus test utilizes a flat glass platen and convex lens to determinethe concentration of a visible or fluorescent penetrant

______ 10.The ceramic block test uses an unfired ceramic disc to determine theapparent brighness of t he spot diameter

______ 11.A special steel block, placed at a 75 0 angle, is used to check theeffectiveness of the emulsier

______ 12.Dry developers are often checked with a hydrometer to insure that theyare still light and fluffy and not settled into a dense mixture

______ 13.The fluorescent penetrant fade test ussually makes use of thee aluminiumtest blocks to perform the test

______ 14.The filtered particle method of penetrant inspection used extra finefluorecent particles that will not pass through a #120 sieve

______ 15.The depth of a discontinuity can be compared by observing the relativeside of brightness of the indication

______ 16.Penetrant that has been transferred to a clean article from th indication onanother aticle can cause a false indication

______ 17.Nonrelevant indications often are actual surface discontinuity

______ 18.If a discontinuity evaluated as being a true indication, the article shouldautomatically be rejected.


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Lesson – 6

This lesson discusses t y p e s o fd i s c o n t i n u i t i e s that can be evaluatedwith the liquid penetrant method.Discontinuities can be divided into threegeneral categories inherent, processing,and service.

Pelajaran ini mendiskusikan jenis cacat yang dapat dievaluasi dengan metodapenetrantCacat dapat dibagi menjadi tiga kategoriumum inherent, processing, dan service.

1. I n h e r e n t – they are usually relatedto discontinuities found in the moltenmetal.I n h e r e n t w r o u g h t d i sc o n t i n u i t i e s– relate to the melting and

solidification of the original ingotbefore it is formed into slabs, blooms,and billets.I n h e r e n t c a st d i sc o n t i n u i t i e s – relate to the melting, casting, andsolidification of a cast article, usuallycaused by inherent variables such asinadequate feeding, gating, excessivepouring temperature, and entrappedgases.

1 . I n h e r e n t – pada umumnyadihubungkan dengan cacat yangditemukan dalam cairan metal.I n h e r e n t w r o u g h t d i s co n t i n u i t ie s – berhubungan dengan peleburan

dan pembekuan ingot (batanglogam) sebelum dibentuk ke dalamslab, bloom, dan billet.I n h e r e n t c a s t d i s c o n t i n u i t i e s –berhubungan dengan peleburan,casting, dan pembekuan artikelcoran, umumnya disebabkan olehberbagai inherent seperti pengisiantidak sempurna, gating, temperaturberlebihan saat menuang, dan gasterperangkap.

2 . P r o c e ss i n g d i s c o n t i n u i t i e s – theyare usually related to the variousmanufacturing processes such asmachining, forming, extruding,rolling, welding, heat treating, andplating.

2. P r o c e s s i n g d i s c o n t i n u i t i e s – umumnya dihubungkan denganberbagai proses pabrikasi sepertipengerjaan dengan messin,pembentukan, extruding, rolling,pengelasan, perlakuan panas, danpelapisan.

3 . S er v i c e d i s c o n t i n u i t i e s – they arerelated to the various serviceconditions such as stress corrosion,fatigue, and erosion.

3. S e r v i c e d i s c o n t i n u i t i e s – dihubungkan dengan berbagaikondisi operasi seperti karatan,kelelahan, dan erosi.

R e m e m b e r ; when you use the liquidpenetrant method, you can find onlythose discontinuities which are open tothe surface.H o w e v er , during the manufacturingprocess, many discontinuities that weresubsurface can be made open to thesurface by machining, grinding, and thelike.

I n g a t , jika anda menggunakan metodacairan penetrant, anda dapat temukanhanya cacat-cacat yang terbuka dipermukaan.Bagaimanapun , selama prosespabrikasi, banyak cacat sub permukaandapat dibuat terbuka ke permukaan olehpengerjaan dengan messin,penggerindaan, dan semacamnya.

R em e m b e r t h a t d i sc o n t i n u i t i e s a r e

n o t n e c e s sa r i l y d e f e c t s , any indicationthat is found by the inspector is called a

I n g a t b a h w a ca c a t t i d a k s e l a lu

d e f e c t , setiap cacat yang ditemukanoleh inspektur disebut cacat sampai


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discontinuity until it can be identified andevaluated as to the effect it will have onthe service of the part.Listed below are some typicaldiscontinuities that should be recognizedwhen doing any type of nondestructivetest. (a more detailed study of typicaldiscontinuities can be obtained byreading programmed instructionhandbook PI-4-1.)

dapat diidentifikasi dan dievaluasi efekpada operasional alat

Daftar di bawah adalah beberapa jeniscacat yang harus dikenali ketikamelakukan setiap jenis pengujiannondestructive (lebih terperinci belajarcacat dapat diperoleh denganpembacaan programmed instruction PI-4-1.)

D i sc o n t i n u i t i e s t r a p p e d i n t h e i n g o t during the steel-making process maycause additional types of discontinuities

as the steel is used in the manufactureof an article.

Ca ca t t e r p e r a n g k a p d a l a m i n g o t selama proses pembuatan baja dapatmenyebabkan tambahan jenis cacat

seperti baja digunakan dalampembuatan artikel (alat)

T h e r e a r e t h r e e m a i n t y p e s o fd i s co n t i n u i t i e s f o u n d i n in g o t s .1. P o r o s i t y – caused by in trapped gas

in the molten metal.2. N o n - m e t a l l i c i n c l u s io n s – caused

by impurities accidentally included inthe molten metal.

3. P i p e – caused by shrinkage at thecenter of the ingot as the molten

metal solidifies.

A d a t i g a j e n i s u t a m a c a ca t y a n gd i t e m u k a n d a l am i n g o t1. P o r o s i t a s – disebabkan oleh gas

terperangkap dalam cairan metal2. I n k l u s i n o n - m e t a l i c – disebabkan

kejadian ketidak murnian masukdalam dalam cairan metal

3. P i p e – disebabkan oleh penyusutandi tengah (pusat) ingot saat cairan

metal mengeras


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The “hot top” is usually cropped off toremove most of the abovediscontinuities.

When in ingot is further processed intoslabs, blooms, and billets, it is possiblefor the discontinuities to change size andshape.As a billet is flattened and spread out,nonmetallic inclusions may cause alamination. Pipe and porosity could alsocause laminations in the same manneras shown below.

" Bagian atas " pada umumnya dipotonguntuk menghilangkan cacat di atasKapan ingot/batang logam adalah lebih

Jika ingot dipeoses lebih lanjut menjadislab, bloom, dan billet, kemungkinancacat berubah ukuran dan bentuk.

Seperti billet diratakan dan dibentangkan(dirol), inklusi nonmetallic dapatmenyebabkan laminasi. Pipe danporositas dapat juga menyebabkanlaminasi dalam cara yang sama seperti

ditunjukkan di bawah.

As a billet is rolled into bar stock,nonmetallic inclusions are squeezed outinto longer and thinner discontinuitiescalled stingers.

Billet dirol menjadi batangan, inklusi nonmetalik ditekan menjadi lebih panjangdan cacat tipis disebut stringer


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As a billet is rolled into round bar stock,surface irregularities may cause seams.

Seams are caused by folding of metaldue to improper rolling or by a crack inthe billet as shown below.

Billet dirol menjadi batangan bulat,ketidak beraturan permukaan dapatmenyebabkan seam.Seam disebabkan oleh lipatan metaldikarenakan ketidak sempurnaan saatngerol atau retak dalam billet sepertiditunjukkan di bawah.

A seam could also occur when the billetis formed into a rectangular bar asshown below:

Seam dapat juga terjadi ketika billetdibentuk menjadi batangan segi-empatseperti ditunjukkan di bawah:


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Forging discontinuities occur when metalis hammered or pressed into shape,usually while the metal is very hot.A forged part gains strength due to thegrain flow taking the shape of the die,and the process is shown below.A forging lap is caused by folding ofmetal on the surface of the forging,usually when some of the forging metalis squeezed out between the two dies.

Cacat tempaan terjadi ketika metalditempa atau ditekan ke dalam bentuk,umumnya saat metal sangat panas.Barang tempaan semakin kuat karenabutiran menjadi bentuk tempaan, danproses ditunjukkan di bawah.Lipatan tempaan disebabkan oleh lipatanmetal pada permukaan tempaan,umumnya ketika sebagian metal ditekanantara dua die.

A forging burst is a rupture caused byforging at improper temperatures. Burstsmay be either internal or open to the

surface as shown below.

Forging burst adalah pecahandisebabkan oleh tempaan padatemperatur tidak tepat. Burst mungkin

internal atau terbuka pada permukaanseperti ditunjukkan di bawah.

Casting discontinuities occur whenmolten metal is poured into a mold andallowed to solidify.A cold shut is caused when molten metalis poured over solidified metal as shownbelow:

Cacat tuangan terjadi ketika cairanmetal dituangkan ke dalam cetakan dandibiarkankan untuk mengeras.Cold shut disebabkan ketika cairan metaldituangkan di atas metal keras sepertiditunjukkan di bawah:


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Hot tears (shrinkage cracks) occur whenthere is unequal shrinkage between lightand heavy sections as shown below:

Hot tear (retak susut) terjadi ketika adapenyusutan berbeda antara bagian yangtipis dan tebal seperti ditunjukkan dibawah:

Shrinkage cavities are usually caused by

lack of enough molten metal to fill thespace created by shrinkage, similar topipe in the ingot.

Rongga penyusutan pada umumnya

disebabkan oleh ketiadaan cairan metalyang cukup untuk mengisi ruang yangdiciptakan oleh penyusutan, serupadengan pipe pada ingot


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M i cr o s h r i n k a g e is usually many smallsubsurface holes that appear at the gateof the casting.

Micro shrinkage can also occur when themolten metal must flow from a thinsection into a thicker section of a

casting.

P en y u s u t a n m i k r o pada umumnyabanyak lubang kecil di bawahpermukaan yang muncul di pintutuangan.Penyusutan mikro dapat juga terjadiketika cairan metal harus mengalir daribagian tuangan tipis ke bagian yang

lebih tebalBlow holes are small holes at the surfaceof the casting caused by gas whichcomes from the mold itself. Many moldsare made of sand, and when moltenmetal comes into contact with the mold,the water in the sand is released assteam.

Blow hole adalah lubang kecil dipermukaan tuangan disebabkan oleh gasdari cairan sendiri. Banyak cetakandibuat dari pasir, dan ketika cairan metalberhubungan dengan cetakan, air dalampasir hilang sebagai uap air.

Porosity is caused by entrapped gas.

Porosity is usually subsurface but canoccur on the surface depending on thedesign of the mold.

Porositas disebabkan oleh gasterperangkap.Porositas pada umumnya di bawahpermukaan, tetapi dapat terjadi padapermukaan yang tergantung padarancangan cetakan.

Grinding crack, are a processing-typediscontinuity caused by stresses whichare built up from excess heat createdbetween grinding wheel and metal.Grinding cracks will usually occur at rightangles to the rotation of the grindingwheel.

Retak gerinda adalah jenis cacat prosesdisebabkan oleh tekanan yangmenciptakan panas berlebihan batugerinda dan metal.Retak gerinda umumnya terjadi padasudut 90

˚

terhadap putaran gerinda


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Heat treat cracks are often caused bythe stresses built up during heating andcooling. Unequal cooling between lightand heavy sections may cause heat treatcracks.

Heat treat cracks have no specificdirection and usually start at sharp

corners which act as stress concentrationpoints.

Heat treat cracks (retak) seringdisebabkan oleh tegangan selamapemanasan dan pendinginan. Perbedaanpendinginan antara bagian yang tipisdan bagian yang tebal dapatmenyebabkan heat treat cracksHeat treat crack tidak punya arahspesifik dan pada umumnya mulai pada

sudut yang tajam yang bertindaksebagai titik konsentrasi tegangan.Fatigue cracks are service-typediscontinuities that are usually open tothe surface where they start fromconcentration points.Fatigue cracks are possible only after thepart is placed into service. But may bethe result of porosity, inclusions or otherdiscontinuities in a highly stressed metalpart.

Fatique cracks (lelah) adalah jenis cacatservice pada umumnya terbuka padapermukaan dimana retak dimulai darititik konsentrasi.Fatique cracks (lelah) hanya mungkinsetelah barang digunakan. Tetapimungkin porositas, inklusi atau cacatlain pada barang dengan tegangan tinggi


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We l d i n g d i s c o n t i n u i t i e s – thefollowing are types of processingdiscontinuities.

C a c a t l a s – berikut adalah jenis cacatproses


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Quiz 6

______ 1. The general category of processing discontinuities relates todiscontinuities caused during manufacturing processes such as welding,extruding, and heat trating

______ 2. During the steel-making process the top of the ingot is usually removedto help eliminate such discontinuities as pipe, porosity and nonmetallicinclusions

______ 3. When a billet as rolled into bar stock, a nonmetallic inclusion could beformed into a longer and thinner discontinuity called a stringer

______ 4. Porosity an a billet could cause a lamination if the etal were formed intoa flat plate

______ 5. Seams are usually subsurface discontinuities caused by improper rollingof a billet into round stock

______ 6. During the rolling of a billet into round bar stock, the grain in the metalforms perpendicular to the direction of rolling

______ 7. In the forging operation, underheated metal will not allow the metal toflow properly and may cause “forging seams”

______ 8. Forging bursts are considered subsurface discontinuities found in theforging process and are caused by inadequate heating of the forged part

______ 9. Cold shuts are common disontinuities found in the forging process andare caused by inadequate heating of the forged part

______ 10. Blow holes are subsurface discontinuities commonly found in the castparts

______ 11. Because cold metal occupies more space than hot metal, there is thedanger of “hot tears” duing in the casting process

______ 12. Porosity is often caused by entrapped gas that is expanded during thheating and pressing in the forging process.

______ 13. Microshrinkage is often found at the gate of a casting and is usuallysubsurface.

______ 14. Grinding cracks are usually at right angles to the direction of grindingand are caused by the heat build up between the grinding wheel andmetal.

______ 15. Heat treat cracks are often associated with stress concentration pointsof the part being heat treated.

______ 16. Porosity may lead to a fatigue crack in a highly stress part ______ 17. Crater cracks and tungsten inclusions are both associated with

discontinuities formed during the welding process. ______ 18. Lack of penetration and lack of fusion both refer to the same type of

working discontinuity


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Lesson – 7

Identification and comparison ofdiscontinuities that can be found with theliquid penetrant process.The student is asked to study thephotographs and descriptions of typicaldiscontinuities as printed in the PTclassroom training handbook (CT-6-2)Each of the specific discontinuitiesillustrated are divided into three generalcategories: inherent, processing, andservice.

Identifikasi dan perbandingan cacat yangdapat ditemukan dengan proses cairanpenetrantSiswa diminta untuk mempeljari foto danuraian jenis cacat seperti dicetak dalamPT classroom training hand book ( CT-6-2)Setiap cacat spesifik yang digambarkandibagi menjadi tiga kategori umum:inherent, process, dan service.

Cold shut Page 7 – 10Fillet crack Page 7 – 12Grinding crack Page 7 – 15Heat affected zone cracking Page 7 – 19Heat treat cracks Page 7 – 21Shrinkage cracks Page 7 – 24Thread cracks Pa

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PT Dual Language Rev 1