循环淬火对22MnCrNiMo系泊链钢组织和性能的影响

22MnCrNiMo钢是用于制造R4级海洋工程系泊链的新型钢种,为了使其达到R4S级系泊链的综合力学性能,比较系统地研究了22MnCrNiMo钢两次快速加热循环淬火调质热处理工艺及组织和力学性能的变化规律.结果表明,该钢经循环淬火处理后获得了细小均匀的奥氏体晶粒,晶粒平均尺寸由原始轧制态的38μm细化到约10μm,综合性能得到明显提高.尤其是韧性与一次加热淬火调质处理的相比,-20℃冲击功值提高近40%,完全达到R4S级系泊链的综合力学性能要求.

Effects of Cyclic Heat Treatment on Microstructure and Mechanical Properties of 22MnCrNiMo Mooring Chain Steel

22MnCrNiMo steel was used to fabricate offshore engineering R4 mooring chain, for the purpose of obtaining the mechanical properties required by R4S, Cyclic heat treatment was applied. The cyclic heat treatment consisted of double quenching and tempering (DQT). The effects of quenching and tempering temperature on microstructure and mechanical properties were investigated. The results show that the uniform and fine grained structure with enhanced mechanical properties is obtained after double quenching and tempering. The austenite grain size is refined from 38 μm to about 10 μm. The strength and ductility both improve significantly. Especially, compared with the quenching and tempering (QT) process, the ductility increases by approximately 40%. The techaical criteria of R4S mooting chain can be freely met.