Post Weld Heat Treatment of a stainless steel to carbon steel weldment
Post Weld Heat Treatment of a stainless steel to carbon steel weldment
(OP)
Hi Guys, Looking for some help here.
We have a situation involving a deaerator that I would like some assistance with.
We are instructed to run a stainless steel vent through a carbon steel shell that is 1" thick. Given that this is a deaerator, we will have to stress relieve the weld to prevent thermal shocking cracks and damage.
Aside from the need to qualify a procedure to do this, is tehre any reason not to perform the weld explained above? I had always thought you should try to avoid post weld heat treatments of stainless steel due to the possiblity of additional sensitization past what already happens during the weld.
Can you guys provide any insight as to what would be the best course of action here? I am planning to install a carbon steel line to penetrate the vessel wall and then do the dis-similar metal weld away from the deaerator.
Also, if you have any good links to resources concerning sensitization of stainless steel, please share them.
Thanks in advance for any help.
Rob
We have a situation involving a deaerator that I would like some assistance with.
We are instructed to run a stainless steel vent through a carbon steel shell that is 1" thick. Given that this is a deaerator, we will have to stress relieve the weld to prevent thermal shocking cracks and damage.
Aside from the need to qualify a procedure to do this, is tehre any reason not to perform the weld explained above? I had always thought you should try to avoid post weld heat treatments of stainless steel due to the possiblity of additional sensitization past what already happens during the weld.
Can you guys provide any insight as to what would be the best course of action here? I am planning to install a carbon steel line to penetrate the vessel wall and then do the dis-similar metal weld away from the deaerator.
Also, if you have any good links to resources concerning sensitization of stainless steel, please share them.
Thanks in advance for any help.
Rob





RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
Then you could weld the SS to the extension and not worry about PWHT.
If you PWHT the SS you run the risk of sensitization.
How low is your C content?
The sensitized SS will be much more susceptible to both pitting corrosion and Cl stress corrosion cracking.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
Or you can use a low carbon grade or extra low carbon grade of stainless steel to mitigate sensitization and weld directly to the carbon steel vessel followed by PWHT.
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
RE: Post Weld Heat Treatment of a stainless steel to carbon steel weldment
As usual this site is a great aid in the engineering profession. You guys have basically confirmed what i had thought and i do appreciate the quick responses.
Thanks again to everyone.
Rob