Welding stainless steel to steel 3

[dcruz]

I'm looking for a specification (Mil, AWS ,etc) that describes this process

 

[welding1]

The problem with welding stainless steel to carbon steel is that you create a mixed region between the two which is chrome steel, chrome steel is very hardnable and not what you want in a weld. To overcome this problem use a higher chrome electrode/filler such as a 309 grade. Its welded basically as a stainless steel see

http://home.istar.ca/~bsant/index.html

for further info.

(

http://www.gowelding.com)

 

[Rich2001]

HERE ARE A FEW gtaw (TIG) WELDING PROCEDURES (AMPERAGE, VOLTAGE & FILLER) FOR CARBON STEEL (P1) TO 300 SERIES STAINLESS STEEL (P8) (JOINT DETAIL NOT GIVEN)

Base Metal "Type 301, 302, 304 TO CARBON STEEL P1-P8"
Weld Joint (mm) - - - - - -
Thickness 1.6 2.5 3.2 4.8 6.4 12.7
Weld Position Flat Flat Flat Flat Flat Flat
Filler Wire (mm) - - - - - -
Filler Wire Specification AWS A5.9 AWS A5.9 AWS A5.9 AWS A5.9 AWS A5.9 AWS A5.9
Filler Wire Class ER 309 ER 309 ER 309 ER 309 ER 309 ER 309
Square Butt 1.6 1.6 or 2.4 2.4 3.2 4 6
Lap Fillet 1.6 1.6 or 2.4 2.4 3.2 4 6
Intside Corner Fillet 1.6 1.6 or 2.4 2.4 3.2 4 6
Outside Corner Fillet 1.6 1.6 or 2.4 2.4 3.2 4 6
Double Fillet Tee 1.6 1.6 or 2.4 2.4 3.2 4 6
Single Bevel Corner - - - - 4 -
Single Vee Butt - - - - 4 6
Double Vee Butt - - - - - 6
Filler Wire Extension - - - - - -
Extension - - - - - -
Electrode & Cup - - - - - -
Electrode Type Tungsten (EWTh-1/-2) Tungsten (EWTh-1/-2) Tungsten (EWTh-1/-2) Tungsten (EWTh-1/-2) Tungsten (EWTh-1/-2) Tungsten (EWTh-1/-2)
Diameter (mm) 1.6 1.6 1.6 2.4 to 3.2 3.2 3.2 or 4.0
Number of Passes 1 1 1 1 1 to 2 2 to 3
Gass Nozzle Cup Type Ceramic Ceramic Ceramic Ceramic (butt/corner) Water-cooled Water-cooled
- Ceramic Ceramic Ceramic Water-cooled (lap/tee) Water-cooled Water-cooled
Current (amps) - - - - - -
Current Type DC neg DC neg DC neg DC neg DC neg DC neg
Square Butt 80-100 100-120 120-140 200-250 275-350 350-450
Lap Fillet 100-120 110-130 130-150 225-275 300-375 375-475
Intside Corner Fillet 80-100 100-120 120-140 200-250 275-350 350-450
Outside Corner Fillet 80-100 100-120 120-140 200-250 275-350 350-450
Double Fillet Tee 90-100 11-130 130-150 225-275 300-375 375-475
Single Bevel Corner - - - - 275-350 -
Single Vee Butt - - - - 275-350 350-450
Double Vee Butt - - - - - 350-450
Welding Speed (mm/sec) - - - - - -
Square Butt 5.1 5.1 5.1 4.2 2.1 hard to predict
Lap Fillet 4.2 4.2 4.2 3.4 2.1 hard to predict
Intside Corner Fillet 5.1 5.1 5.1 4.2 2.1 hard to predict
Outside Corner Fillet 5.1 5.1 5.1 4.2 2.1 hard to predict
Double Fillet Tee 4.2 4.2 4.2 3.4 2.1 hard to predict
Single Bevel Corner - - - - 2.1 hard to predict
Single Vee Butt - - - - 2.1 hard to predict
Double Vee Butt - - - - - hard to predict
Gas Argon Argon Argon Argon Argon Argon
Gas Flowrate (L/min) 5 5 5 6 6 7
Gas Pressure (kPa) 140 140 140 140 140 140
Gas Nozzle Limits (ceramic) up to 250 amps up to 250 amps up to 250 amps up to 250 amps - -
(water-cooled) - - - > 250 Amps > 250 Amps > 250 Amps
Out of Position Welding - - - - - -
Vertical and Overhead Current reduce by 10-20% reduce by 10-20% reduce by 10-20% reduce by 10-20% reduce by 10-20% reduce by 10-20%


RICH

 

[MickE]

For tanks, we normaly weld the carbon steel to a stainless "backing" plate, the same material as the tank and welded to it.
This is quite common practice for welding mild steel legs to stainless tanks.
There should also be a small "weep" hole in the backing plate.