HEAVY WELDING SHOP

1. DIFFERENT WELDING PROCESS USED IN HEAVY WELDING SHOP (H.W.S.)-

Electric arc welding.

Gas welding.

Forging welding.

Joining of two component by gas electric arc or forge of same or different material homogeneous and dense joint is called welding.

2. Blocks in DLW-HWS

a. ALCO(American Locomotive) block Power V Type6 cylinder 2300hp engine12 cylinder 2600hp 45’ alignment16 cylinder 3300hp 45’alignment

b. GM(general Motor) block or EMD(ElectroMotive Division) block Power 16 cylinder 4000hp

20 ylinder 5000hp

3. ALCO components

(a) Saddle

No. of use widthIntermediate Saddle 07 4.5”Center Saddle 01 6.75”

T Saddle 01 4.625”

b. Foundation Plate L R Two ends free and generator end. L and R

Foundation plates are decided by Generator.

c. Splines

d. Out side walls

width

L 20mm

R

e. Middle deck

Width

L 40mm

R

f. Inside wall Width L 16mm R

g. Top deck L R

In spine welding root run takes place from 1,3,5,7,9 and then 2,4,6,8.In root run, 4.5 to 5mm electode is used for welding.After root welding 6.5mm electode is used.X-ray quality joints are produced in ALCO.

4.Weldind types in HWSa. Manual metal arc welding(MMAW)b. Gas metal aarc welding(GMAV)c. Submerged welding – shielding is provided by flux. On the basis of use - Internal submerge welding - External submerge weldingCO2 and agroshield(Argon 82% and CO2 18%). CO2 creates shield and wt off the contact of flux from environment and prevent oxidation of metal.5. Tandon welding:- Used for heavy metal deposition. Use A.C. and D.C. current both for welding. DC arc lead AC arc transition welding process. Heat input is very low. Good penetration is obtained. It is one time welding process while in internal and external submerged welding the process can be repeated several times.6. Stress releaving:- After complete block fabrication heat treatment is done. We put block into diesel furnace for 28hours. Temprature arises into diesel furnance. At rate 0f 50’ per hour and reach upto 450’C and then rises at the rate of 30’c per hour upto 640’c. At 640’c block is kept in furnance

for 10 hours and its temp. Reaches at range of 250-280’c.Coating:- Electrode is coated by iron dust and other filler material. Coalting is done for shielding of welding process.Type of coating:-a. Low coating – Deposition efficiency 110%.b.Medium coating - Deposition efficiency 110-129%c. Heavy coating - Deposition efficiency 129-140%d.Superheavy Coating - Deposition efficiency 140-

220%.

Deposition Efficiency:- It is defined as the ratio of amount of materisl included is weld to the amount of material supplied.

HEAT TREATMENT SHOP (H.T.S.)

Heat treatment means heating job above r.c. temprature and there should be phase change.

(i) Induction hardening.

(ii) Carburising.

Induction hardening:- Copper coil (99.9pct Cu). High AC coil is used for Induction hardening. AC current setup magnetic field creat eddy current which immidietly heat the job. It is used to heat surface only not to core. Because current at the sutface only.

Carburising:-

Main piston Pin. Impeler gear. Cam roller.

Enrichment of carbon % in job is carburising.Types:-1. Pack solid furnance.2. Gas solid furnance.

PSF:- Impeler gear 925’c heated and is healed in iron box. Barium carbonate is used for promoting carburising process.

Iron is covered by fire clay and left for 16-18 hours. Carbon is first absorbed at surface and then induced to surface and after 16-18 hours we take out immidietely cooled in oil well. We haave to cool in 20-25 seconds. Due to decarburising scaling is obtained on surface. This hardening is first hardening.

The second hardening is done at 840’c for 2 hours sacking period.

Induction hardening does not change chemical composition. Whereas carburising changes chemical composition.

Normalising is used to remove bended structure.

Annealing is used to remove extra hardness.

Engine Testing:-

Engine test operation sequence:

1. Bare inspection under screen and fitting over screen.

2. Water circulation.3. Lube oil filling and check deflection cranckshft.4. Lube oil circulator.5. Pre runs no load – 3runs 5,10,30 minutes(400rpm).6. Intermediate runs 12 run’s of 30 minutes duration

each from 400rpm to1000rpm. Load 68 to 2330bhp.7. Check over speed trio of re-check three times.8. Check brake in nozzles and set tapped clearance.9. Inspection before first hour performance.10. First hour performance on full load.11. Base inspection.12. Second hour performance on full load.13. Attend defects of first hour performance.14. Final base inspection.15. Check engine deficiencies.16. Engine clearance.

- Project submitted by

Bhushan Kumar.