合金元素对Cr-Mo钢第二类回火脆性影响研究综述

对于一些长期在中温条件下服役的Cr-Mo钢(2.25Cr1Mo),由于钢中P、S等有害杂质元素在服役过程中不断向晶界偏聚,降低了晶界结合力,致使该类钢出现第二类回火脆性这一关键问题.为了探寻降低这类Cr-Mo钢第二类回火脆性倾向的有效方法,提高材料安全服役可靠性,从溶质元素偏聚机制出发,总结分析了合金元素晶界偏聚及改善...

Effect of alloying elements addition on the secondary tempering brittleness of Cr-Mo steels review

For some Cr-Mo steels(2.25Cr1Mo)which are usually serviced at medium temperature for a long time,the critical problem of the second type temper embrittlement is existed in these steels because of the continuous segregations of P,S and other harmful impurities to the grain boundary during the service.In order to explore some effective methods to reduce the temper embrittlement tendency of this kind of Cr-Mo steels and improve the reliability of the material,starting from the segregation mechanism of solute elements,the intrinsic essences of alloy elements segregation at grain boundary and its function on improving the temper brittleness of steel were analyzed.The segregation phenomena of several common elements and their influence on temper embrittlement of steel were mainly summarized.At the same time,the main reasons for the difference between theoretical calculation and experimental study are also analyzed.It is expected to provide some effective methods for temper embrittlement of medium temperature steel during long-term service,and offer some references for the study of grain boundary segregation behavior of alloying elements in future.