Dear Devang, This P11 material is already affected by creep, the microstructures reveal it. It has accumulation of microstructural damages due to prolong operation (10 years) decreasing their load bearing capacity, with formation of Cr carbides at the grain boundaries and carbon dissolution in the matrix. You have to notify the plant of the need to change that section of pipe affected by creep, due to the risk of sudden cracking, with operational consequences. On the other hand, under normal conditions, the welding of P11 material (1 ¼ Cr - ½ Mo) should has maximum hardness of 225 HBN for service at high temperature operating. A good solution is use the material P22 (2 ¼ Cr-1/2 Mo). Propose it. Regards, Ramon Briceno http://www.linkedin.com/in/ramonbriceno-metalengineer Sent from Mail for Windows 10 From: Devang Majithia Sent: Friday, May 28, 2021 1:27 AM To: materials-welding@googlegroups.com Subject: [MW:32392] LAS P11...
Materials selection, welding, forming, Heat treatment, corrossion, NDT