Q & T Procedure for Feild Welding

[OdyQC]

I am with a maintenance company that is looking to get into some work a a SAGD facility in Northern Alberta. I have been given the task to write a Q & T procedure for doing completed weld joints in the field and am having trouble looking for where to start. I know what Q & T is however I do not know enough for a procdure.

Thanks for any info that is provided.

TMc

 

[Duwe6]

The problem will be obtaining a proper Quench. Quenching is time-critical, and quenchant fluid dependent.

 

[redpicker]

You have to start with the materials used and joint design. What is the chemistry of the base materials? Thickness? Filler Metal?

Next, what are the requirements of completed weld? Why do you need to heat treat the weld in the first place?

You have to define the above before you can determine the process parameters needed. You may be able to achieve acceptable results with a N & T or maybe just a stress relieve.

Obviously, performing a Q&T operation in the field on a weldment has its own challenges.

rp

 

[metengr]

There are ways to work around a field Q&T by modifying preheat, and interpass temperature. In fact, it is not recommended to try to accomplish a field Q&T of welded joints because you will alter the bulk properties of the material.

 

[OdyQC]

Thanks for the replies. After some more digging I found out my upper management team does not know the difference between a Q & T heat treating procedure and a WPS for welding Q&T materials.

I told them that there is so many variables to Q&T'ing material that it is over the companies 'head' to be messing around with 24" X 2" thick welds then Q&T'ing them. The welding we can do though.