汽车螺旋悬架弹簧用钢55SiCrA组织和性能研究.pdf

籍 钢 技 术 2 0 1 6 年 第 4 期 ANGANG TECHNOLOGY 总 第 4 0 0 期 (3 ^ 免与开 汽车螺旋悬架弹簧用钢55SiCrA组织和性能研究 张博，郭大勇，高航，马立国，王秉喜 (鞍钢集团钢铁研究院，辽宁鞍山114009) 摘要：采用热膨胀法结合显微金相与硬度法，在 LINSEIS 7 8 R IT A 相变仪上测定了 55SiC rA 弹簧钢的临界点温度和连续冷却转变曲线，研究了冷却速度对组织和硬度的影响规 律。在此基础上，进行了控轧控冷工业试验。结果表明，当冷速臆2 益/ s 时，转变产物为少量铁素 体、珠光体，珠光体硬度随冷速增大而增大；当冷速逸5 益/ s 时，转变产物为珠光体、马氏体；当 冷速逸20益/ s 时，转变产物为马氏体，硬度随冷速增大而增大；现场控轧控冷的试验钢抗拉强 度达到1163 MPa ，伸长率为13%，面缩率为49%，综合力学性能良好，满足了用户的使用要求。 关键词院汽车悬架螺旋弹簧;55SiC rA 弹簧钢；C C T 曲线；显微组织；力学性能 中图分类号：TG 142 文献标识码：A 文章编号院1006-4613(2016)04-0035-04 Study on Microstructures and Properties of 55SiCrA Steel Used for Coil Springs of Automotive Suspension System Zhang Bo , Guo Dayong , Gao Hang , Ma Liguo , Wang Bingxi (Iron Steel Research Institutes of Ansteel Group Corporation , Anshan 114009, Liaoning , China ) Abstract : By the thermal expansion method , metalloscopy method and hardness method the temperature of the 55SiCrA spring steel at critical points and its continuous cooling transformation curves (CCT ) was measured on LINSEIS 78 RITA . The laws of effect of cooling rates on microstructures and hardness of the steel were studied . Based on the studies the industrial test on the thermo mechanical control process (TMCP ) was carried out . The test results show that the resultants by transformation include a little bit of ferrite and pearlite as the cooling rate is less than or equal to 2 益/s and the hardness of pearlite increases with the increasement of the cooling rate . But the resultants by transformation turn into martensite and pearlite as the cooling rate is more than or equal t