PWHT on 13CrMo 4-5

[Lucas Villa Fernandez]

Good afternoon everyone,

I would like to comment on some doubts that I have about PWHT to make a new PQR for the 13CrMo 4-5 material.
We have to weld 8 Thermowells TW15 + welding sockets TA115 of 13CrMo 4-5 material with 9mm thickness, on an 18-inch CS P235GH pipe with 10mm thickness

Due to the thickness of the components, the welds must be treated with PWHT.
The temperatures given in EN ISO 13480 for 13CrMo 4-5 are 630 - 700 degrees Celsius.

For the P235GH the temperatures are 550 - 600 degrees Celsius from 35mm thick.

The EN ISO 15614-1 standard says that the PWHT can vary by 20 degrees Celsius from the temperature used in the PQR.

My question is, if we make a PQR welding 13CRMo 4-5 + PWHT with temperatures between 630 - 700 degrees, we need another PQR for welding the combined materials (13CrMo 4-5+P235GH) due to the minimum temperature difference of 13CrMo 4 -5 630Gr. and the maximum of the P235GH