2．25Cr－1Mo钢焊接接头蠕变过程中碳化物相研究的现状及趋势

The Studying Situation and Tendency of Carbides in 2.25Cr-1Mo Steel Welded Joints during Creep

2．25Cr－1Mo钢焊接接头蠕变过程中碳化物相研究的现状及趋势@杨德新...

Cr-1Mo steel is one of the ferritic heat-resisting steels used widely.Its high creep resist￣ance is mainly due to the dispersion of the carbides in it.In this paper,according to the author and hiscollaborators’work in the recent decade,the studying situation and tendency of the carbides in 2.25Cr-1Mo steel welded joints are summarized.Generally,there are five kinds of carbides in the welded joints(Weld,HAZ,Matrix):M 3C,M 2C,M 7C 3,M 23 C 6 and M 6C.During service,the sub-stable car￣bides will transform into stable ones.In this process,the speed of the transformation and the re-dispersion of the carbides will influence the creep resistance and the service life directly.So,it is neces￣sary to study the carbide’s transformation and its orientation relationship with the matrix during creep,in order to probe the mechanism of the creep strengthening.At present,the differences of the various carbides’orientation relationship are studied,so as to learn the combined strength of the carbides with the matrix,as well as the acting rule of the carbides to the motion of the dislocations.After that,the micro-mechanism of the creep strengthening can be revealed.