Welding ht-treated to non-ht treated CS in wet H2S service
Welding ht-treated to non-ht treated CS in wet H2S service
(OP)
A client is asking whether he can weld heat treated ASTM 106 Grade B to non-heat treated ASTM 106 Grade B. This is > 10,000 ppm wet H2S service.
I suggested a flange-joint to preserve the treatment but he insists on welding.
How will welding affect the heat treatment?
Is there any recourse to preventing damage of the heat-treated pipe?
I suggested a flange-joint to preserve the treatment but he insists on welding.
How will welding affect the heat treatment?
Is there any recourse to preventing damage of the heat-treated pipe?





RE: Welding ht-treated to non-ht treated CS in wet H2S service
Welding will locally alter the base metal properties resulting in potentially harmful residual tensile stresses and hardened material around the weld region. This is why post weld heat treatment is necessary for specific service conditions.
Welding can be done but may require post weld heat treatment, if PWHT was the original requirement for service.
RE: Welding ht-treated to non-ht treated CS in wet H2S service
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Welding ht-treated to non-ht treated CS in wet H2S service
- Find API RP581-2008, Table 9.3 & 9.4
- Where is the spec break? Is the joint belonging to wet sour or non-wet sour?
- pH in the service?
- Hardness on base metal and new HAZs by welding?
- The client's spec requirements.
The most critical requirement for seamless pipe weld in wet sour service is the hardness. So when the hardness on HAZ is below 200 BHN without PWHT, it may be acceptable unless there are some remarkable issues from the above confirmation.
Thomas Eun
RE: Welding ht-treated to non-ht treated CS in wet H2S service
LM
RE: Welding ht-treated to non-ht treated CS in wet H2S service
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Welding ht-treated to non-ht treated CS in wet H2S service
LM
RE: Welding ht-treated to non-ht treated CS in wet H2S service
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Welding ht-treated to non-ht treated CS in wet H2S service
RE: Welding ht-treated to non-ht treated CS in wet H2S service
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04