摘要
在盐浴加热条件下对弹簧钢60Si2CrVA 进行了多种循环热处理试验。结果表明:常规热处理后钢的奥氏体晶粒直径约为20μm(8级),采用循环热处理则可晶粒细化至5μm(12级)。在所研究的几种循环热处理工艺中,循环淬火显著地提高强度,但对塑性和韧性影响不大;提出的一种改进的循环热处理使各项机械性能指标得到提高,尤其是显著提高屈服强度和断裂韧性。对热处理后的显微组织进行了分析。指出改进的循环热处理对性能的改善归因于奥氏体品粒的细化和挛晶马氏体量的减少。
Thermal cycling treatments were applied to 60Si2CrVA spring steel by using salt bath heating method.The results showed that these thermal cycl- ing treatments provided a better refinement in grain size(refined to 5 μm) compared with that from conventional heat treatment(refined to 20 μm). Among the heat treatments employed,two cyclic quench process increased the strength considerably,while the ductility and toughnee remained unaltered, and the introduction of a modified cyclic process improved all mechanical properties investigated.The microstructures obtained after the heat treatments were analysed.The improvements noted in the modified cyclic treatment were interpreted as due to the refinement of austenite grain size and a reduction in the amount of twinned plate martensite.
关键词
循环热处理
晶粒细化
弹簧钢
thermal cycling
grain refinement
spring steel
