Read about the process in WeldED magazine

AWI - WeldED Index

Vol 2 2010 WeldED

Sponsors Shindaiwa http://www.shindaiwa.com.au/

South Pacific Welding Group http://www.spwgroup.com.au/home.asp

SafeTac http://www.safetac.com.au

Bureau Veritas http://www.bureauveritas.com.au

Southern Cross Industrial Supplies http://www.scis.com.au

Technoweld http://www.technoweld.com.au

Hardface Technologys http://www.hardface.com.au

3834 Weld Management [email protected]

Cover Page Shindaiwa our new GOLD sponsor. The AWI welcomes Shindaiwa.

Australasian Project Supplies are the sole distributor of

Japanese Shindaiwa welders and generators in Australia.

Originally selling the industry leading DGW400DM 400

Amp dual machine they then diversified their range into a

200Amp welder, 500Amp welder and a range of super

silent environmentally friendly generators custom built for

the Australian market.

AWI operates this service for members. Information and comments in AWI publications are the opinions of specific individuals and companies, and may not reflect the position of AWI or its Directors. Information on procedures and processes herein, as well as any advice given, are not sanctioned by AWI, and AWI makes no representation or warranty as to their validity, nor is AWI liable for any injury or harm arising from such entries or from reliance on any entries. Participants should independently verify the validity of information prior to placing any reliance thereon.

Index Shindaiwa 2 Shindaiwa

Pickling & Passivation 3 Stainless Surface treatment explained

L&A Pressure 8 A snap shot of an AWI member company

The Lighter Side 10 My encounter with HF

AWI Progress 11 Progress Update of the AWI

Defects and Design 13 Case study on how design affects the defect level

Sponsors 17 A thank you to those who brought you "WeldED"

Shindaiwa 2

Vol 2 2010 WeldED

New Shindaiwa Welder hits the ground running

Australasian Project Supplies are the sole distributor of

Japanese Shindaiwa welders and generators in Australia.

Originally selling the industry leading DGW400DM 400

Amp dual machine they then diversified their range into

a 200Amp welder, 500Amp welder and a range of super

silent environmentally friendly generators custom built

for the Australian market.

Over the past 8 years the Shindaiwa and APS team have

spent countless hours making all their welding and

generating machines to not only suit the Australian

conditions and requirements but to exceed them.

Through exceptional build quality, reliability and

performance the Shindaiwa range is suited to even the

harshest Australian environments. Through this

dedication to quality Shindaiwa customers enjoy

machines that are easy to use, maintain and are

economical to own and run.

Last year Shindaiwa released the highly anticipated

DGW500DM/ANZ, featuring a dual welding function

using Wire Feeders or Stick electrodes, 57dbA Super

Silenced enclosure, 18kVA of Auxiliary Power, a 3 Way

Switch and Battery Isolator standard making this the

ultimate diesel welding machine.

The DGW500DM/ANZ has been taken on by hire

companies Tru Blu Hire, Coates Hire and GCS with

excellent utilisation and results on sites such as Gorgan,

South Australian Desalination plant and the Alkimos Pipe

Water treatment plant in Perth. If it is exceptional

welding performance combined with the latest in

Japanese technology you require, look no further than

Shindaiwa.

Please visit the Shindaiwa Australia Webpage for further

product and dealer information:

www.shindaiwa.com.au

Pickling & Passivation 3

Vol 2 2010 WeldED

Pickling & Passivation

Introduction We are all aware that there are many methods of

restoring the corrosion resistance of stainless steels

such as traditional pickling pastes, electro polishing,

mechanical abrasion etc. Each method of restoring

corrosion resistance has its own unique traits and can

be employed in a variety of situations which will have

varying degrees of success. This article will attempt to

explain the various methods available to the

Australian welding and fabrication industry but will

not attempt to rate one method against another.

Instead; it will leave it up to the reader to decide the

best method in any given situation after taking into

account time, cost and safety factors.

Corrosion Resistance Because the corrosion resistance of stainless steels is

due to a ‘passive’, chromium rich oxide layer, the

mechanism by which stainless steels regain this layer

is called ‘passivation’. The corrosion resistance of

stainless steel arises from this oxide film because it

forms a natural protective layer on the surface of the

steel. The oxide layer is extremely thin, but very

tenacious and chemically stable, which is why it is

commonly referred to as ‘passive’. The film is formed

when chromium reacts with oxygen and forms

Chromium Oxide (Cr2O3).The maximum corrosion

resistance of stainless steels can only occur when the

Chromium Oxide layer develops as an unbroken film

across the entire metal surface.

As a word of warning, stainless steels cannot be

considered corrosion resistant in all service

conditions. Depending on the type (composition) of

the steel there will be certain service conditions

where the ‘passive state’ of the stainless steel is

broken down and prevented from reforming. Here the

surface becomes ‘active’ resulting in corrosion. These

conditions occur in small areas, such as at mechanical

joints, tight corners or at incomplete or poorly

finished welds. The result can be a form of localised

attack (crevice or pitting corrosion – Fig 1). Stainless

steel can also corrode in service if there is

contamination of the surface. The high temperature

induced during welding also results in severe

chromium depletion not only at the weld surface but

throughout the heat affected area. Therefore just

removing surface material such as oxide scale is only

half the job as the weld area is still chromium

depleted relative to the parent stainless steel.

Critically when stainless steel is depleted of chromium

its corrosive resistance is severely reduced. The weld

is therefore vulnerable to pitting and crevice

corrosion.

Both pickling and passivation and electro‐polishing are

chemical treatments applied to the surface of

stainless steel to remove contaminants and assist the

formation of a continuous chromium‐oxide, passive

film. There are several methods to restore the

corrosion resistance of stainless steels. Some of these

methods under discussion will also increase the

thickness of the chromium oxide layer.

Methods of Restoring Corrosion Resistance Prior to any attempts to restore the oxide layer,

removal of oil, grease or inorganic contaminants by

degreasing of the material’s surface is an especially

important operation. Acid pickling and electro‐

polishing methods will not break through an oil or

grease barrier and mechanical abrasion methods

(sanding, sand blasting etc) tend to ‘push’ surface

contaminants into the material rather than rid the

surface of them.

Fig 1 Photo revealing localised attack


Vol 2 2010 WeldED

This corrosion resistance can only be achieved if

proper cleaning and finishing operations are carried

out after any fabrication process as there will have

been damage to the surface condition.

The next sections will give some detail on restoring

corrosion resistance.

Auto-passivation Stainless steels will naturally form a chromium‐oxide

layer if the surface is exposed to sufficient oxygen.

This occurs automatically and instantaneously but will

increase in thickness after its initial formation. In this

way stainless steels keep their corrosion resistance

even where mechanical damage (e.g. scratching or

machining) occurs. The chromium in stainless steels is

primarily responsible for the formation of the oxide

layer and for this to occur there must be a minimum

of 10.5% (by weight) of chromium. The mechanism by

which the oxide layer forms is called self‐passivation

or auto passivation.

Passivation As discussed above, passivation naturally occurs on

the surfaces of stainless steels, but it might

sometimes be necessary to assist the process. No

metal is removed during this process. The quality and

thickness of the chromium oxide layer is quickly

developed during acid passivation. The chemical used

is Nitric acid (HNO3) and used alone will only passivate

stainless steel. Common passivation treatments will

clean the steel surface of free iron contaminants. Care

must be taken in selecting and using passivation

treatments to ensure the selected treatment will

target the contaminant. Passivation does not usually

Result in a marked change in appearance of the steel

surface. Stainless parts or surfaces must be rid of

grease and oils that contaminate the surface. The

nitric acid used for this passivation process will not

remove these types of contaminants and the surface

will become mottled and an incomplete passive layer

likely to result.

Pickling and Passivation This method is the most commonly employed in

industry and is the one best known. It is the brush on

paste, where the solution is mixed with an inert

carrier that is used to treat selected areas such as

welds. Spray on treatments is also available for larger

surface areas (Fig 2). Pickling involves the removal of a

thin layer of the stainless steel surface with the use of

strong acids, typically a Nitric and Hydrofluoric (HF)

acid combination. Procedures incorporating pickling

solutions of nitric and hydrofluoric acids remove the

scale and the underlying chromium depleted layer and

restore the corrosion resistance. Pickling solutions

also remove contaminants such as ferrous and ferric

oxide particles.

Pickling solutions other than mixtures of nitric and

hydrofluoric acids exist and can be used for

specialised applications. One example, used in the

wine industry, is for the use of citric acids to treat the

stainless steel surface of the large wine vats.

Fig 3 Before and After treatment

Fig 2 Large vessel being treated


Vol 2 2010 WeldED

Mechanical Cleaning with tools such as mechanically grinding,

buffing, wire brushing and/or polishing the weld is a

surface treatment that is also employed by the

stainless fabrication industry.

Mechanical removal may leave abrasive or other

particles embedded. The corrosion resistance of the

stainless steel is affected by the roughness of the

surface after polishing, with a marked decrease of the

corrosion resistance as the surface roughness

increases above a Ra value of about 0.5 micron

(0.005mm). This roughly corresponds to the surface

produced by grinding with 320 grit abrasives.

Iron‐oxides, polishing compounds and other materials

can then become entrapped in the distorted

structure, creating a vulnerability point for surface

corrosion so mechanical finishing of stainless steel

material is typically a poor corrosive resistant finish.

Electro-Polishing Electro‐polishing is a useful alternative to pickling.

Metal removal is achieved, but usually results in a

bright, smooth and more highly corrosion resistant

finish Pickling is the process where

Research has shown that the best way to post‐weld

finish stainless steel is electro‐polishing, which is an

electrochemical process that increases density of the

chromium throughout the weld surface and therefore

the ability to create the chromium oxide film. Electro‐

polishing provides the most dense and durable

passive film that it is possible to achieve.

Electro‐polishing has two benefits beyond removing

weld scale. One is that it selectively dissolves the

microscopic high points of the stainless and creates a

microscopically smoother surface on which

contaminates can not bind or hide. Figures 3 and 4

reveal this effect.

The second benefit is that it selectively removes iron

at a higher rate than chromium which is why the

chromium density is increased.

Electro‐polishing can be accomplished by immersion of the item in a large, acid‐containing bath. It is impractical to perform this on‐site but it can also be achieved with a portable electro‐polishing machine or weld cleaning machine that runs on a direct current. This method uses an electrochemical cell on the metal surface, akin to electro‐polishing.

The weldment is connected as the anode at which metal is dissolved, removing the oxide layer, leaving a clean surface.

With a direct current and specific solution chemistry, electro‐polishing can occur, which results in a high surface lustre. Figure 5 reveals the results of electro‐polishing on the surface of a vessel.

Fig 3 Material surface before polishing

Fig 4 Material surface after polishing

Fig 5 Photo of tank after immersion


Vol 2 2010 WeldED

Best results are achieved with electro‐polished direct

current which gives a significantly better result than

mechanical cleaning and pickling paste.

It may be advantageous to neutralise the acid with an

alkali before the rinsing step.

Safety Both pickling and passivation solutions can employ

dangerous acids that can damage both the operator

and the environment if not handled correctly. Normal

precautions for safety should be followed and always

consult Materials Safety Data Sheets and product

packaging for detailed advice.

Conclusion In conclusion, it can be stated that from this

discussion, there is a hierarchy of results based on the

process employed to improve the corrosion resistance

of stainless steels. The table below broadly outlines

from worst case to best case.

Process Result

As‐welded Detrimental to corrosion

resistance

Mechanical

polishing/abrasion

May leave abrasive

embedded

Corrosion resistance of the

stainless steel is affected by

the roughness of the

surface

Typically a poor corrosive

resistant finish

Acid Passivation

The quality and thickness of

the chromium oxide layer is

quickly developed

Will clean the steel surface

of free iron contaminants.

Surfaces must be degreased

prior to use

Pickling & Passivation

Solutions of HNO3 and HF

remove scale and the

underlying chromium

depleted layer

Good restoration of

corrosion resistance

Solutions will remove

contaminants

Can be readily used on‐site

and on large and small

surfaces

Electro‐polishing

Best method of post‐weld

finishing stainless steel

Increases density of the

chromium

Creates a microscopically

smoother surface

Minor portability issues,

portable DC

electropolishing machines

are available

Table 1 Hierarchy of results


Vol 2 2010 WeldED

Stainless pickling acids are highly corrosive to carbon

steel. It is essential that all acids are thoroughly

removed by rinsing the component after completing

the process. Residual hydrofluoric acid will initiate

pitting corrosion.

ASTM A380 Standard Practice for Cleaning, Descaling

and Passivation of Stainless Steel Parts, Equipment

and Systems is a valuable source of information on

pickling and passivation treatments.

The two figures below highlight a fabrication that has

undergone a post weld treatment. In a corrosive

environment the item identified in Figure 7 will

significantly outlast the component that has had no

post‐weld finishing.

References 1. Euro Inox –Materials and Applications Series,

Volume 4

2. Stainless Steel Post Weld Finishing/Post

Fabrication Clean up ‐A Technical Review by

Metal Science Technologies August 2010.

3. ASSDA – Australian Stainless Steel

Development Association

Useful Links 1. www.assda.asn.au

2. www.euro-inox.org

3. www.avestawelding.com

4. www.metalscience.com.au

Author:

Alec Kimber IWE

Fig 6 No post‐weld treatment Fig 7 After post‐weld treatment

L&A Pressure 8

Vol 2 2010 WeldED

L&A Pressure Welding Pty Ltd AWI Member Company Overview

L&A Pressure Welding Pty Ltd is an established Sydney based supplier of

pressure equipment and has a long history of providing solutions and equipment

to projects ranging from small maintenance jobs to large LNG developments.

Involvement in several major projects over the last 5 years has been used to

build up the company’s knowledge and services in engineering design, project

and quality system management.

The company operates from a 5700m2 undercover work shop with a base staff of

approximately 45 shop employees.

Figure 1 – 80mm thick boiler

with in‐house lined tubes

Facilities include two PWHT furnaces for equipment up to 20m long x 4.0m in diameter; plate rolling up to 50mm

thick and hydro testing equipment up to 80,000kPa. Overhead cranes provide an 80 tonne lifting capacity; handling

of heavier units has been achieved by utilising jacking systems. An on site machine shop supports the fabrication

process, enabling most activities to be handled in house.

Manufacturing experience covers a range of equipment from typical

pressure vessel, heat exchanger and column design through to specialised

waste heat boiler fabrication. Complete supply, assembly and factory

acceptance testing of multiple air cooler units and piping skids have

recently been executed providing clients with a single delivery option for

their work packages.

Figure 2 – FOB Delivery of assembled skids

Involvement in major project work has extended our design and fabrication scope to include specialised transport

and installation engineering, a service that assists clients requiring free‐

on‐board and site delivery terms.

Extensive involvement in the pressure industry over many years has

created a significant amount of experience in design, covering

equipment that meets all classes of AS1210, ASME VIII and TEMA codes.

Design is carried out using PV Elite and Nozzle pro, drafting is supported

through AutoCAD & Inventor for 3D applications, pipe spooling projects

utilise CADworx. Specialised projects have extended design scope into

areas of high temperature creep and cyclic analysis through FEA.

Figure 3 – loading U‐Tube Bundle

L&A Pressure 9

Vol 2 2010 WeldED

The diverse project scope undertaken over time has exposed our project,

manufacturing and welding personnel to a broad range of materials and

technical challenges. Through in‐house development of welding

procedures the company has established a range of options for welding

exotic materials such as; Super Duplex, Inconel, Titanium, Hastelloy, Monel

and clad plated carbon steels. Construction of heavy wall carbon steel

equipment (150mm thick) has seen the development of specialised

manufacturing and heat treatment processes to achieve low temperature

impact, tensile & hardness requirements.

Design, procurement and manufacturing are supported by a vast

network of specialised engineering and supplier services sourced

both locally and internationally. L&A are also currently supporting

related postgraduate research programs and engineering studies as

well as maintaining a continual training environment for apprentice

boilermakers and welders. L&A Pressure Welding are committed to

supporting Australian manufacturing and are looking forward to

continue support from the oil and gas sector in their development

of Australian resources

Photos of Other Recent Projects

Figure 4 ‐ Inconel 825 Header box Figure 7 ‐ 316 Vessel for Export

Fig 4 SAW on heavy LF2 nozzle to shell joint

Fig 5 Welding on 50mm thick CS vessel

The Lighter Side of Welding 10

Vol 2 2010 WeldED

My encounter with HF

Last weekend as I was walking home from my day at the

shipyard; I saw something at the Pawn Shop that sparked

my interest. Our 22nd wedding anniversary was due and I

was looking for a little something extra for my wife. What I

saw advertised in the window was a 100,000‐volt, purse‐

sized taser. The effects of the taser were supposed to be

short lived, with no long‐term adverse affect on your

assailant, allowing her adequate time to retreat to safety....

WAY TOO COOL!

Long story short, I paid for it and brought it home. I loaded

two AAA batteries in it and pushed the button. Nothing! I

was disappointed. I learned, however, that if I pushed the

button AND pressed it against a metal surface at the same

time; I'd get the blue arch of electricity darting back and

forth between the prongs, just like the high frequency on

my TIG torch……….Awesome!!! Okay, so I was home alone

with this new toy, thinking to myself that it couldn't be all

that bad with only two AAA batteries, right?!! There I sat in

my recliner, my cat Gracie sitting on the arm and looking on

intently (trusting little soul) while I was reading the

directions and thinking that I really needed to try this thing

out on a flesh & blood moving target. I must admit I thought

about zapping Gracie (for a fraction of a second) and

thought better of it. She is such a sweet cat. But, if I was

going to give this thing to my wife to protect herself against

a mugger, I did want some assurance that it would work as

advertised. Was I wrong? So, I’m sat there in a pair of shorts

and my singlet with my reading glasses perched delicately

on the bridge of my nose, directions in one hand, and taser

in another and itching to try it out!!

The directions said that a one‐second burst would shock

and disorient your assailant; a two‐second burst was

supposed to cause muscle spasms and a major loss of bodily

control; a three‐second burst would purportedly make your

assailant flop on the ground like a fish out of water. Any

burst longer than three seconds would be wasting the

batteries. Now I’ve been on the end of those HF tingles and

the damp electrode shocks you get and all the while I'm

looking at this little taser‐thing measuring about 200mm

long, less than 20mm in circumference; pretty cute really

and loaded with ONLY two tiny AAA batteries thinking to

myself, "no possible way!" I'm sitting there alone, Gracie

looking on and I’m thinking that a one‐second burst from

such a tiny little thing couldn't hurt all that bad so I decided

to give myself a one‐second burst just for the hell of it.

What happened next is almost beyond description, but I'll

do my best...

I touched the prongs to my naked thigh, pushed the button,

and……….HOLY MOTHER OF GOD!!!

I'm pretty sure at that VERY SAME MOMENT…..a pack of

Wallabies forwards ran in through the side door, picked me

and the recliner up……and body slammed us both on the

carpet, over and over and over again. I vaguely recall

waking up on my side in the foetal position, with tears

running from my bulging eyeballs, my body was soaking

wet, both of my nipples were on fire and I couldn’t feel

anything from the waist down!!! My left arm was tucked

under my body in the oddest position, and my legs were

kicking imaginary objects!! A minute or so later (I can't be

sure, as time was a relative thing at that point), I collected

what little wits I had left and managed to sit up and survey

the landscape. My bent reading glasses were on the mantel

of the fireplace. How did they up get there???

The cat was making meowing sounds I had never heard

before and seemed to be clinging to the picture rail….half

way up the wall!! The recliner was across the other side of

the room…upside down and I was wet due to a problem I

seemed to have had with my bladder!! My triceps, right

thigh and both nipples were still twitching. My face felt like

it had been shot up with Novocain, and my bottom lip

seemed to weigh 20kgs!!

Note: If you ever feel compelled to "mug" yourself with a

taser, one note of caution: it is DEFINITELY not the same as

a damp electrode or a tingle from a GTAW HF unit!!....and

there is no such thing as a one‐second burst when you zap

yourself. You will not let go of the bloody thing until it is

dislodged from your hand by violently thrashing about on

the floor. A three second burst would be considered

conservative.

Progress Update 11

Vol 2 2010 WeldED

Progress Update on the AWI

Well, it has now been two months since the Australian

Welding Institute has been launched and what an

interesting two months!

In the days after launching, we have received letters,

emails, faxes, phone calls, even personal visits from

people offering all manner of support and

congratulations. This has come not just from the welding

industry itself but from many associated industries such

as mining, NDT, teaching, certification bodies, career

guidance, railways and from the cutting industry, plasma,

gas cutting, grinding etc.

We are amazed at the interest we have received via our

website. Although it is still in its infancy and will develop

over the coming months, the huge number of hits and

downloads has taken us by surprise. We have had to

triple our bandwidth to cope. The interest has not just

been from within Australia. To date, we have had people

from 25 different countries connect to our website.

It seems the most popular downloads have been the

calculators and technical forms in the "Services" and

"Technical Resources" sections.

Shindaiwa has become our first Gold Sponsor. They were

quickly followed by SPW (South Pacific Welding Group)

as our Silver Sponsor with SafeTac, Southern Cross

Industrial Supplies and Bureau Veritas becoming Bronze

Sponsors.

Although membership is currently free of charge, we

have had most people contributing something to the

Institute to become members. While some have not

contributed money, they have offered their time or

expertise to assist in some way. This has been

tremendously encouraging.

All members should by now have received their

membership card. This idea came about after the first

WeldEd had been issued so members were not notified

that they would receive one.

Hopefully it came as a pleasant surprise for everyone.

One eagle‐eyed member pointed out a "deliberate"

mistake in our first technical article on Duplex Steels. OK,

it was a typo. (That's our excuse!).

If you didn't spot it, it was on page 9 under Welding

Methods – GTAW. It should have read “This method of

welding should employ DCEN…..” (direct current

electrode negative) instead of the incorrect DCEP.

Thanks Scott.

We are currently in the process of completing our

Education and Certification working group. We still have

much work to do but we believe this will be up and

running by the time the next WeldEd is out.

While we have received plenty of support, we would

love to see more feedback on what you think would be

interesting or what subjects you want more information

on.

When we contact

people directly, there

is no shortage of ideas

or suggestions on

what direction we

should take or what

aspects of the

industry they would

love to know more about.

This ranges from information on jobs, welding

parameters, what gas to use, AC or DC current, what

Standard applies, where do I get more training, safety

issues etc. etc.

Most people seem to have the same concerns or

interests. This is YOUR institute. Our job is to support

YOU.

Please contact us at [email protected] with

your questions and suggestions (good or bad).

Welding Regards,

The Directors.

Progress Update 12

Vol 2 2010 WeldED

Progress Update on the AWI

Website.

The AWI website has been put together as a portal for

members to access information and technical resources.

It has now been up for approx 8 weeks and the response

has been fantastic, with 40,000 hits in this period. We

have had to upgrade our bandwidth to cope with the

traffic.

There are some fantastic resources available on the

technical resources page such as;

The Cigweld Handbook

Migatronic Technical Sheets

CE Calculator

Heat Input Calculator

Consumable Calculator

The forum has also had a unbelievable launch with many

Q&A being posted. The forum is there so members can

assist one another with technical or other issues. The

Q&A are available indefinitely as a virtual technical

library for members.

We have also registered a Facebook page

www.facebook.com/austwelding giving members

updates on our progress and a media for real time

feedback.

We encourage you to get online and visit

www.austwelding.com.au and have a look for yourself.

To contribute to the technical resource page, please

email any documents, templates or technical

information to [email protected].

Regards

The Directors

AWI

Design and Defects 13

Vol 2 2010 WeldED

Case Study:

How design can contribute to increased costs and rework

Introduction

The purpose of this document is to detail a case

study of how design can contribute to increased

costs and rework, by using inappropriate detailing

and joint configurations.

To achieve welds to an acceptable standard in a

reasonable time period requires good access to

the joints to be welded. Without good access to

the joints the operators struggle to see what they

are doing, struggle to move in a smooth

consistent manner required for producing

acceptable welds, Operator duty cycle (amount of

arc on time) drops dramatically because of

operator fatigue due to cramped conditions and

the likelihood of workplace accidents increases.

The Data

This case study has been developed on data

assembled from my observations of welding

operators trying to weld these joints, from

personal experience trying to get in there myself,

to weld the joints and physical measurements

taken from the job. The data was gathered in the

period of August 2006 – October 2006.

Actual conditions when welding with Gas Metal

Arc Welding (GMA/MIG) were such that, out of

20 qualified and tested operators, only three

where capable of producing AS1554.1 compliant

welds in these very cramped positions, this ratio

would be typical in most engineering workshops.

Images of observations are seen in the examples

and are as follows:

Overall view of

conditions

These images show that a standard welding

helmet cannot get between the members to be

joined


Vol 2 2010 WeldED

The use of special limited access helmets were

used to make access easier, with minimal affect

Actual conditions when operator is welding, this

guy has 82cm waist, right handed.

Considerations:

The larger the operator the lower the access

Consider the use of left and right handed

operators

Image showing you cannot get your head high

enough to get good vision of the joint

Image above showing 82cm waist guy wedged

between members to get access, not only does

it increase difficulty it creates a dangerous

situation due to increased risk of

electrocution, burns, fume inhalation and

physical strain due to ergonomics.

Examples of burns sustained to operators

because they were having to stretch to get

into tight positions when welding resulting in

PPE being less effective (ie jacket riding up)


Vol 2 2010 WeldED

Image showing a larger operator (92cm waist)

trying to access joints in the flat position. Keep

in mind these operators have to be able to

move the hands along a predetermined path

at a rate of about 200 to 300mm per minute

and the operator typically needs their eyes to

be at reading distance from the joint to be

able to focus on what they are doing.

Issues arising from the data

The issue that presented itself when looking at

the data is that in this case the detailing /

product design was such, that access to some

of the joints was very limited.

If you cannot get your head into a position to

see what you are doing when welding you are

fighting an uphill battle, your eyes need to be

at reading distance or it makes welding

operations very difficult. As the data shows the

actual dimension of a welding helmet is

greater than that of the opening the operators

need to get into to see the joint, this is not

something a draftsperson would be aware of.

Seeing the joint is the first requirement, being

able to move along the joint slowly, consistently

and accurately whilst the arc is on is the next

challenge and in these conditions it is nearly

impossible. Indeed some joints were impossible

to weld and had to be modified, where possible,

to suit.

This limited access as seen in this case

contributed to

increased weld discontinuities

therefore increased welding inspection costs to detect discontinuities and sentence to code, to determine defects

increased rework to repair defects

lower operator duty cycle and higher injury rates due to cramped conditions

increased consumable and labour costs because of rework.

Summary

Prior to detailing projects, one must understand

the fabrication and welding processes that will be

used in construction, the processes applications,

limitations and access requirements to ensure the

design is practical and economical to produce.

Fabricators must carefully review drawings at

tender stage to ensure the component they are

about to build is achievable and if there is any

doubt they should go back to the client with their

concerns.

Author:

Graham Fry ‐ Technoweld Pty. Ltd.

Membership Application

Title: (Mr, Mrs, Ms) _______________________________________________________ Name: _____________________________________________________________ Date of Birth: _____________________________________________________________ Company: _____________________________________________________________ Position: _____________________________________________________________ Address: _____________________________________________________________ Suburb: _____________________________________________________________ State: ______________________________ Post Code: _________________________ Email Address: ________________________________________________________ Contact Phone Number: __________________________________________________ Type of Membership: (circle one) Corporate Individual I, the undersigned, agree to be bound by the constitution of the Australian Welding Institute (available by request) Signature: _________________________________ Date: ______________________________________ Please return to your local representative Or email to [email protected] Or Post to PO Box 618, Penrith, NSW 2751

AWI is a Not for Profit Body for the Welding Industry Voluntary Membership Contribution Amount: $________ Membership is free, but if you contribute a voluntary contribution you go into a draw for a Cigweld Inverter (1st prize) and a Sperian Welding Helmet (2nd prize) (both drawn 1/12/10). Contribution can be submitted by direct transfer to Bank: BankWest, Account: Australian Welding Institute, BSB: 302-966 Account Number: 0101604 Remittance: [email protected] Membership is free, with the long term view of charging a minimum value to cover the cost of administration of the organisation as the organisation grows and offers additional services to you as a member. The Directors of the AWI thank you in advance for your support

Membership Benefits

The provision of a professional network for members to exchange information and ideas relating to all things welding

Subscription to the E-News Bulletin “WeldED”

The opportunity to join a national organisation whose main objectives are to:

Promote the advancement of the Australian welding and

fabrication industry Promote its members and their services to others in the welding

industry Create a network of people who are passionate about and want to

aid the Australian welding and fabrication industry Endorsement of Australian welding and inspection qualifications

Encourage participation in working groups to further develop your

knowledge in your area of specialisation and aid other members

Documents

Read about the process in WeldED magazine