[MW:15873] Query P1 Gr. 3 Barrier layer PWHT

Dear Expert,

I have query regarding application  of PWHT on forging base material of P1 Gr. 3 (SA765 Gr. IV--Maximum certified Hardness 180 HRB) after barrier layer deposit of 3 to 4 mm.

The code of construction is ASME sec. VIII Div. 1

It is clearly understood that barrier layer is not for corrosion resistant.

Should it be 620 deg C or 550- 560 Deg C??

Customer specification is for PWHT at 620 deg C

We are worried about base material loosing partial tempering properties/Mechanical properties.

Any reply with reference to code/ published experimental paper / similar experience for knowledge sharing would be beneficial.

Thanks in advance.

 

Best Regards,
MUKESH

---