PWHT for 5%Cr

Date 01-26-2004 07:57

Dear all
I wanna do PWHT for welding joint of material A335-P5 with bellow characteristic:
wall thickness= 8 mm max
pipe diameter = 2" & 4"
we must do PWHT as soon as possible and I saw in ASME B31.3 that for P No.5 holding time is min 2 hr but I didnt see anything about time rating(increasing and cooling).I do PWHT with rating 150C/hr and hold it 2hr and after PWHT hardness was 140 HB .
Is it possible that we increase rating temp. and decrease holding time?
Please help me as soon as possible.

best regards
A.A.Sharif

By burikg

Date 01-26-2004 14:57

could you pls give me UNS or WNr number of that SS steel?

By pipewelder_1999 (****)

Date 01-26-2004 16:25

Take a look at Para 331.2.1 and 331.2.2 and see if that answers your question. I may have misunderstood and I'm using th 99 code.

Have a good day

Gerald Austin

By alisharif (*)

Date 01-27-2004 12:44

dear sir
I read all paragraph of ASME B31.3 but I didnt see anything about heating and cooling rate in PWHT of alloy steel 5% Cr .
I wanna know the best graph for PWHT.

best regards
A.A.sharif

By pipewelder_1999 (****)

Date 01-27-2004 15:01

Sorry wouldn't know that. I thought you wanted to know if you could vary the time/temp from that listed in B31.

Have a good day

gerald

By RonG

Date 01-27-2004 17:29

Rule of the thumb
After 315' C/ ramp up at 93' C max/ hour / Soak / Ramp down to 315' C at 93' C per hour.

That is our standard most that alloy.

The way I read it no PWHT is required for that wall thickness.