Post weld heat treatment

can we perform PWHT on ss material

PWHT usually stand for “post weld heat treatment” of carbon steels and low alloy steels. it is performed at 600-700°C.
as per ASME code, austenitic stainless steel should not normally be post weld heat treated at 600-700°C because this can lead to dimensionnal variations and loss of mechanical properties and corrosion resistance (precipitation of harmful intermetallic phases, sigma phase embrittlement, 475C embrittlement, sensitization by chromium carbide precipitatation, …). refer to ASME section dedicated to PWHT.


PWHT not required on stainless steel material, unless require by WPS.


It’s recommend for stainless steel TP347 Only

General not need to perform PWHT for weldment. Could you share spec. requirement?

Tp347 ,321,348 these are stabilized grades and have sufficient titanium or cb to prevent sensitization .
As bien stated u can do PWHT on these ss only when there is a project requirement or your WPS is qualified with PWHT unless no need of PWHT


Bundle of thanks

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