Is it require to qualify a WPS for repairs after Stress relieving? We have a WPS qualified with PWHT (soaking temp 610 Deg C; 1 Hr for 25mm thk). But there is a repair in the butt weld after SR (No RT done before SR). After repair if we Heat treat the joint the soaking time will become 2Hr for 25mm thk. So without qualify a new WPS can we use the same WPS/only SR is allowed?

Hi,

the key to your question is QW-407.2. Please have a look at one of the tables of QW-250 which is applicable for your process. The above mentioned paragraph is a supplementary essential variable.

That means:
(a) If impact tests are not required for your joint the above paragragh is not applicable and the WPS is the right WPS.

(b) If impact tests are required for your joint the above paragragh is applicable and the WPS is not the right WPS.
But in this case you get more problems with the WPS for the remaining deposited weld metal. This weld metal gets in consequence of the repair PWHT two times the holding time. But according to the above mentioned paragraph the supporting PQR has to had “at least 80% of the aggregate times at temperature” of the actual joint.

Hope that helps.

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Kind regards,
Juergen Fleischfresser