摘要
42 Cr Mo经 86 0℃循环淬火 3次 ,5 5 0℃回火处理以后 ,奥氏体晶粒平均直径可细化到 7μm左右 ,因而所形成的马氏体板条长度大大缩短。这种短小的回火板条马氏体相对具有较低的疲劳缺口敏感性并可使屈服强度和伸长率同时提高。其中疲劳强度提高 2 4% ,对于相同的强度级别来说 ,伸长率可提高 2 5 %。晶粒细化以后 ,42 Cr Mo的疲劳裂纹常常起源于表面擦伤处 。
After treatment of direct and reverse martensite transformation at 860 ℃ three times fowllowed by tempering at 550 ℃, the austenite grain of 42CrMo can be re-fined to about 7 μm and so the length of formed lath martensite is shortened greatly. This structure is of lower sensitivity to notch fatigue and makes the yield strength as well as elongation increase. The fatigue strength can be increased by 24 %. For the steels of same strength level, the elongation can be increased by 25 %. The crack is usually imitated at the scratches on surface of test pieces after grain refinement.
出处
《钢铁》
CAS
CSCD
北大核心
2002年第10期52-56,共5页
Iron and Steel
基金
国家 973项目资助 ( G19980 6 15 )
