stainless cracking on fusion tig weld

Date 10-15-2008 16:42

Any input from one of the pro's?

Just fusion welding a 316L s/s flange onto 316L s/s tube. 5 of them welded great. 4 of them crack after I clean them. I am sure that the tube is 316L but the flange is a custom purchased part. So apperatntly what they sent us is 316L but I was not provided material certs. Does anyone know what series of stainless would have cracking characteristics when being welded to 316L?

By Lawrence (*****)

Date 10-15-2008 17:11

Savvy,

When you say "Just fusion welding" do you mean autogenous?

300 series stainless is about the toughest stuff out there. But, fillets welds without filler, especially if they are restrained in a fixture may be the culprit.

The distortion forces inherent with Stainless applied to a weld joint with reduced cross sectional thickness that is produced by an autogenous fillet can be a cause of cracking.

Looking at your material certs is a wise first step... But process control may be an issue as well.

Tell us more about the thickness of the flanges and tubes and I'm sure you will get more good responses.