Sigma phase on SS grade H

[0707]

A practical way to detect sigma phase on old austenitic stainless steels of grade H, is to shoot, TIG electrode over the pipe surface. If the shoot makes small cracks the pipe should have sigma phase.
Does anybody heard about this?

Regards

Luis Marques

 

[metengr]

No. I wouldn't hang my hard hat on this method.

 

[EdStainless]

A lot of other types of things could cause the same cracking.
Taking samples for micros is the only way to know.
Though taking large enough samples to do the full range of mechanical testing (impacts too) would tell you more.
In the end you don't care whay the properties have changed, you just need to know if they have.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm