Abstract: The effect of deforming temperature 800 ~950 ℃ on structure and mechanical properties of steel 55SiCrA (% ： 0. 56C, 1. 42Si, 0. 68Cr) for auto suspension spring has been studied by Gleeble-1500 thermo/mechanical simulator and using optical, electron microscopy and mechanical property test. Results show that with increasing deforming temperature, the starting and finishing temperature of pearlite transformation gradually drop and the spacing of lamellar in pearlite decreases ； with defonning temperature 850 ~ 900℃, the spacing of lamellar in pearlite is 130 - 140 nm, and the steel has best comprehensive mechanical properties i. e. tensile strength 1 075 ~ 1 090 MPa with reduction of area 43. 5% 〜44. 0%.

Key words: Spring Steel 55SiCrA, Deforming Temperature, Structure, Mechanical Property

摘要： 通过Gleeble-1500热/力模拟试验机,采用光学、电子显微技术及力学测试等方法,研究了800～950℃变形温度对汽车悬架用弹簧钢55SiCrA(%:0.56C、1.42Si、0.68Cr)组织和性能的影响。结果表明,随着变形温度的提高,相变开始温度和相变结束温度均逐渐下降,珠光体片层间距逐渐减小,变形温度为850～900℃时,珠光体片层间距为130～140 nm,抗拉强度为1 075～1 090 MPa,断面收缩率43.5%～44.0%,综合力学性能最佳。

关键词: 弹簧钢55SiCrA, 变形温度, 组织, 力学性能