Stainless-carbon galvanic reaction
Stainless-carbon galvanic reaction
(OP)
I have a project where I need to attach a stainless steel structure to a carbon steel structure. The stainless frame is mostly tubes, so bolting would not be practical. Does anyone have experience in attaching stainless to carbon by welding? Will this result in a galvanic reaction that will corrode the steel? AWS D1.6 prescribes how to weld stainless to carbon, but I do not want to interpret this as an endorsement of such a connection.






RE: Stainless-carbon galvanic reaction
What I have found out is: the two can be welded. I have not heard of any galvanic reaction. You should use an electrode that has more chromium in it than the base s.s., since it will be diluted by the c.s. Do this in order to maintain the anti-corrosive properties of the s.s. in the weldment.
e.g., 309 electrode has 20% Cr, whereas type 316 or 304 s.s. has about 18% Cr.
s.s. has higher coef of thermal expn and will distort more readily from heat of welding. It also has lower thermal conductivity and will not dissipate heat as rapidly. Therefor, should use lower current, use skip welds and allow steel to cool between welds.
Sparks from grinding will cause s.s. to rust.
Call for fabricator to be asme chapter IX certified. Make sure welder is experienced with s.s. Someone who has only done c.s. welding will probably screw it up. Try to have this welding done in the shop, not the field.
Austenitic s.s. is most weldable.
I am not an expert is welding or in s.s., but have picked up these tips from a s.s. fabricator. Hope it is some help.
RE: Stainless-carbon galvanic reaction
RE: Stainless-carbon galvanic reaction
I hope any of this helps,
TW
RE: Stainless-carbon galvanic reaction