New PQR Time! ASME IX P4 material;

By jon20013 (*****)

Date 07-20-2005 18:56

Time to run a new PQR, Yippee! Working with SA335, Gr. P11 which is an ASME Section IX P4 base metal; 1.25% chrome, 0.5Mo material. Coupon in this case is actually going to be a 16" pipe, Schedule 80 (0.844" thick).

So, what are some thoughts on preheat? I know I'll have to do PWHT to 1150 - 1250 but I'm more interested in preheat at the moment for control of cracking.

By chall

Date 07-20-2005 19:17

We base our preheat on what is specified in ASME Section B31.1. It may not be the best methodology, but so far we haven't had any problems.

131.4.4 requires 250F preheat for P4 material.

Charles Hall

By jon20013 (*****)

Date 07-20-2005 19:56

Cool, I appreciate the feedback! FYI; SFA-5.28 shows 275 - 325F but I'm just looking for opinions.

By - Date 07-20-2005 20:21

Hi Jon,
The information I have shows a 1 1/4Cr-1/2Mo with a thickness of 0.5 to 1.0 in. (13 to 25 mm) to have a preheat of 300F. (150C). So, you are real close.

Chuck