14.9级高强度汽车紧固件用钢42CrMoVNb调质工艺研究  

Study on Quenching and Tempering Process of 42CrMoVNb Steel for Class 14.9 High Strength Automotive Fasteners

作　　者：王磊 郑宏伟 陈兆勇 WANG Lei;ZHENG Hongwei;CHEN Zhaoyong(Nanjing Integrated Iron and Steel Co.,Ltd,Nanjing 210035,Jiangsu,China)

机构地区：[1]南京钢铁股份有限公司,江苏南京210035

出　　处：《热处理技术与装备》2024年第3期45-49,共5页Heat Treatment Technology and Equipment

摘　　要：通过化学成分分析、金相组织观察以及硬度和力学性能测试,对14.9级高强度汽车紧固件用钢42CrMoVNb的不同调质工艺结果进行分析。研究表明,42CrMoVNb钢在580~600℃回火时,硬度和强度无明显下降,由于在580℃左右回火会产生二次硬化现象;而回火温度高于600℃时强度会迅速下降。42CrMoVNb钢采用奥氏体化温度较高的Q9工艺比采用奥氏体化温度低的Q3工艺得到的晶粒度要粗,且奥氏体化温度越高,其强度和硬度也越高。42CrMoVNb钢的最佳调质工艺为940℃×40 min,油冷+590℃×60 min,空冷和940℃×45 min,油冷+595℃×90 min,空冷。The different quenching and tempering process results of 42CrMoVNb steel for class 14.9 high strength automotive fasteners were analyzed through chemical composition analysis,metallographic structure observation,hardness and mechanical performance testing.The research showed that the hardness and strength had no significantly decrease when tempered between 580℃and 600℃,which was due to the occurrence of secondary hardening when tempering at about 580℃.When the tempering temperature exceeded 600℃,the strength decreased rapidly.The grain size of 42CrMoVNb obtained by Q9 process with higher austenitizing temperature was coarser than that Q3 process with lower austenitizing temperature.The higher the austenitization temperature,the higher the strength and hardness.The best quenching and tempering processes for 42CrMoVNb steel were 940℃×40 min,oil cooling+590℃×60 min,air cooling and 940℃×45 min,oil cooling+595℃×90 min,air cooling.

关 键 词：14.9级 汽车紧固件 调质工艺 42CrMoVNb钢 

分 类 号：TG142.1[一般工业技术—材料科学与工程]