Purging Of Nitrogen

[pandithan]

After Hot bent of SA335 P91, we carried out Normalizing at 1038 degree Celsius and found oxidation/Scale inside Pipe which was difficult to remove. Decided to purge with Argon and found the result is ok ( No Scale). Due to economy, we are now planning for Nitrogen purging instead of Argon.
Whether Nitrogen purging at that Temp will affect any Mechanical/Metallurgical Properties, if so What??[/b]

 

[Aakashjha]

You are talking about the Nitrogen purging during Welding ?

Regards
Aakash Jha

 

[metengr]

A protective atmosphere of nitrogen gas during normalizing will not harm the Grade 91.