V微合金化对55SiCr钢组织和抗延迟断裂性能的影响  

Effect of V microalloying on microstructure and delayed fracture resistance of 55SiCr steel

作　　者：卢茂勇 徐乐[2] 何肖飞[2] 吴润[1] Lu Maoyong;Xu Le;He Xiaofei;Wu Run(School of Materials and Metallurgy,Wuhan University of Science and Technology,Wuhan Hubei 430000,China;Research Institute of Special Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430000 [2]钢铁研究总院有限公司特殊钢研究院,北京100081

出　　处：《金属热处理》2023年第4期190-195,共6页Heat Treatment of Metals

摘　　要：利用光学显微镜(OM)、扫描电镜(SEM)、热力学计算、物理化学相分析和恒载荷缺口拉伸试验,研究了V微合金化对55SiCr弹簧钢淬火和回火后的组织和抗延迟断裂性能的影响。结果表明,由于微合金化元素V的加入,试验钢经淬火和回火后的屈服强度提高了150 MPa,抗拉强度提高了100 MPa,同时获得了尺寸集中在18~36 nm的MC析出相,有效阻止了淬火保温时奥氏体晶粒的长大,将奥氏体晶粒尺寸由15.4μm细化至4.7μm。添加V元素后,在超细晶粒和MC型纳米析出相作为氢陷阱的共同作用下,55SiCr弹簧钢获得高强度和更好的抗延迟断裂性能。Effect of V microalloying on microstructure and delayed fracture resistance of the 55SiCr steel was investigated by means of optical microscope(OM),scanning electron microscope(SEM),thermodynamic calculations,physicochemical phase analysis and constant load notch tensile test.The results show that the yield strength and tensile strength of the quenched and tempered steel are increased by 150 MPa and 100 MPa,respectively,due to the addition of V element.At the same time,MC precipitates with a size of 18-36 nm are obtained,which effectively prevents the growth of austenite grains during heating process of quenching,and the prior austenite grain size is reduced from 15.4μm to 4.7μm.After adding V element,under the combined action of ultrafine grains and MC-type nano-precipitates as hydrogen traps,better delayed fracture resistance of the 55SiCr steel with high strength can be improved.

关 键 词：V微合金化 晶粒细化 力学性能 氢陷阱 抗延迟断裂 

分 类 号：TG142[一般工业技术—材料科学与工程]