PWHT of AUSTENITIC STEEL

[khati]

hello

In ASME code for Austenitic stainless steel ( 18Cr-8Ni) no PWHT requirement is given,
it says “PWHT is neither permitted nor prohibited”, but my service requires PWHT so how should we perfrom the PWHT and what are the factots should I consider while ordering the materials..

Thanks.

 

[gr2vessels]

Ask an engineer experienced in the fabrication of pressure vessels. You are contradicting yourself, what service is against the design code?

 

[stanweld]

Assuming that the Engineer/Owner required PWHT for service, either one will need to provide the appropriate PWHT parameters.

 

[Fizza453]

Khati,

Please see Non-Mandatory Appendix A of ASME Section II Part D, especially A-300.


Nasir
Welding Engineer
DESCON ENGINEERING LIMITED
PAKISTAN

 

[metengr]

PWHT is not required for this material. IF a post weld treatment is required, this would be a solution anneal treatment to ensure maximum corrosion resistance in service. This can be a problem for an object that has been manufactured.

 

[GenB]

ordering materials has nothing to do with the term non
mandatory.
you go ahead and use/make,/design or write your PWHT acordign to the materials used, procedure, PWHT the item and you are done your job.

 

[Duwe6]

And if you use the 'normal' PWHT temperature of 1100 - 1250°F, you have ruined your material. The alloying elements come out of solution on 304/316, etc austenitic stainless steels. As metengr said, the only appropriate Heat Treatment is a full Solution Annealing. "If it isn't broke, don't try to fix it".

Just because an unsophisticated customer asks for PWHT of stainless steel, does not mean that it is appropriate.