摘要
本文主要研究双重淬火工艺(1200℃淬火,650℃回火+860℃淬火)对40Cr钢的显微组织和疲劳裂纹扩展行为的影响。研究结果表明,双重淬火可显著细化奥氏体晶粒和淬火后的显微组织,并使淬火组织中的板条马氏体和马氏体板条间的薄膜状残留奥氏体显著增多。无论是在200℃,或是在400℃回火态,双重淬火均可使da/dN明显降低,a_c明显增大,N_p显著提高。在200℃或400℃回火态,40Cr钢的疲劳断裂机制是沿晶与穿晶的混合,双重淬火对疲劳裂纹扩展初期的断裂机制无明显影响。
The effect of double quenching(1200°CQ. /650°CT. /860°CQ) on the microstructure and behavior of fatigue crack propagation of 40Cr steel is investigated. Exprimental results show that double quenching decreases anstenite grain size, and increaeses the amount of lath martensite and residual austenite film between martensite laths obviously.
After 200℃ or 400℃ tempering, fatigue fracture of 40Cr steel is mixture of intergranular and transgranular. The effect of double quenching on the fracture mechanism at the earlier of crack propagation is not observed.
出处
《金属热处理》
CAS
CSCD
北大核心
1989年第6期3-10,共8页
Heat Treatment of Metals
关键词
结构钢
双重淬火
疲劳裂纹
淬火
doable quenching
structural steel
fatigue crack
