Welding S.S. to C.S.!??

[11echo]

I'm running across a problem, I think, at my new job. In my pass experiences, welding s.stl. to carbon stl. was a no-no as a common practice. It could be done, but you had to qualify the welder per weld! Well here at my present job, they are welding 316L gauge vlv.s to astm A350-LF2 nip-o-lets! ...At least per there material specs. SO... Has something changed to allow this as a common practice? OR should I be jumping up and down waving my arms? I probably should add this is on a ANSI 1500# system, cold temp. ANY HELP would be appreciated!

 

[GRoberts]

Welding of CS to SS is done every day in some industries, an is not an uncommon occurance in most. The welding part is usually the easy one. Corrosion, galvanic action, stresses due to different coefficient of expansion are often the tough issues. Whether it is the right choice for your application, is for the designer to say, because only he/she has all the right info. Should you get alarmed whenever you see this type of weld? Certainly not! Also, most codes do not require what seems to be the excessive qualification required at your last place of work. AWS addresses CS and SS in different codes, but for ASME section IX, in a lot of cases, would not require additional welder qualification. (for instance, a welding welding 316 to 316 using a 316 electrode would be qualified welding 316 to CS using a 309 electrode assuming all other variables remained the same)

 

[Norphlet]

Welding SS and CS by using SS electrodes are common in many industries.