Spotweld 304L SST to CRS?

[Strider17]

Gentlemen:

One of several solutions to an electronics packaging
design would involve spotwelding an SST housing to CRS internal brackets, shields, etc. None of
my metallurgy books address this situation so I would
presume it to be problematic. This design is for a
medical device in an OR environment. Anyone have
any experience with this? TIA...

The more you know, the more you
know you don't know....

 

[Goahead]

Does CRS stand for cold rolled steel?
(It could also mean corrosion resistant steel).
A number of physical characteristics are different in carbon steel vs. stainless steel, so that the outcome of the dissimilar materials spot welding is indeed problematic. Unifying the material if possible would probably be the best solution.

http://www.welding-advisers.com/

 

[Strider17]

Correct, CRS= Cold Rolled Steel...
Thanks for the reply

The more you know, the more you
know you don't know....

 

[rorschach]

corrosion will be your problem. if the CRS side of the weld will not be exposed to moisture, spot passivating to remove heat tint from the weld process will probably be fine.

can the brackets be converted to 304 as well?

 

[TVP]

Strider17,

The short answer is yes, you can spot weld stainless steel to carbon steel. The resistivity of stainless steel is higher than that of carbon steel, and therefore it spot welds very nicely. No coatings to burn through either.

 

[MetalsInc]

You'll end up with a funny looking nugget in most cases. The SS will heat up more (higher resistivity). The result is that the nugget will be bigger on the SS side. You can control this, if required, with some adjustments to the current cycle and the electrode material and geometry. AWS Welding Handbook (8ed - Vol 1 - Page 547) has a brief description of this.