Welding interpass Temperature

[AlejandroFernandez]

Hello.. I'm doing a WPS and when try to define point QW-406, I got freezed, because I was trying to find some information about how determining interpass temperature when welding low carbon steel pipes (ASTM A106B). I read something in asme Section IX and AWS D1.1 but it is not so clear... there talk about "cooling rate" but never specify this value, refer to a chart or formula....
Can some body help me?
Best Regards
Alejandro.

Alejandro Fernández
I+D&I
Sitelca

 

[SJones]

Interpass temperature is that which was recorded in the PQR during welding of the test coupon. It is defined in QW/QB-492 and measurement practice is specifically addressed in ISO 13916.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[metengr]

If your question concerns selection of interpass temperature, not measurement, this value is based on materials to be welded, process used and joint configuration. Normally, selection of the maximum interpass temperature is minimum preheat temperature + additional temperature increase from weld heat input.

For carbon steels, the maximum interpass temperature is around 600 deg F. As you go to higher alloy steels or air hardening steels, the maximum interpass temperature may be less than 600 deg F to avoid adding too much heat into the surrounding base material recognizing that you want to increase arc time for weld production.

 

[stanweld]

Interpass temperature is defined in QW/QB-492. Measurement of it can be made using Temperature indicating crayons, contact or infrared pyrometers, etc. It need not be measured during procedure qualification or recorded on the PQR unless impact testing is required. It is also an essential variable fpr Weld Overlay qualification.

Control during production welding is highly recommended to obtain superior mechanical and corrosion resistance properties.

 

[AlejandroFernandez]

Thanks a lot.. know I understand.

Alejandro Fernández
I+D&I
Sitelca