Study of carbides in a 2.25Cr-1Mo hot reheat steam pipe joint after long-term service

摘要

Carbides in a 2. 25Cr-1 Mo hot reheat steam pipe joint over 20 years service at 565℃, were studied bymeans of H-800 TEM and EDAX. It is concluded that there were M2C, M23C6 and M6C Carbides in the joint, M2C→M6 C and M23C6→M6 C carbide transformations were also found in both base metal and weld metal. Cube-to-Cubeorientation relationship exists between M23C6 and M6C.