作者：孙伟, 张炜星, 张慧星, 胡晓丽, 杜慧起

作者单位：天津中德应用技术大学机械工程学院, 天津 300350

关键词：60Si2Mn;热模拟;CCT曲线;表面脱碳;铁素体分布

摘要：

该文基于Gleeble3800热模拟试验机，运用热压法研究60Si2Mn弹簧钢连续冷却过程中的冷速和温度转变曲线，依据曲线斜率变化获取相变点和临界冷却速率，进而绘制60Si2Mn弹簧钢连续冷却转变（continuous cooling transition, CCT）曲线。根据CCT曲线，选择合理的斯太尔摩工艺冷却控制参数，并通过实际生产验证工艺效果。结果表明，CCT曲线与组织演化规律具有很好的对应关系。当冷却速度介于1~10 ℃/s时，组织为铁素体和珠光体组织，并且随着冷却速率的增加，铁素体含量逐渐减少，珠光体含量有所增加。为实现表面脱碳和铁素体分布的良好控制，要将冷速控制5~8 ℃/s，所有规格弹簧钢试样表面脱碳控制在180 μm以内，同时铁素体分布趋于均匀，为后续深加工创造有利条件。该文工作为60Si2Mn弹簧部件的组织控制、性能优化等方面提供科学依据与理论支撑，对提升60Si2Mn使用寿命具有工程应用价值。

Study on control of continuous cooling structure of 60Si2Mn spring steel
SUN Wei, ZHANG Weixing, ZHANG Huixing, HU Xiaoli, DU Huiqi
School of Materials Engineering, Tianjin Sino-German University of Applied Science, Tianjin 300350, China
Abstract: The cooling rate and temperature transition curve of 60Si2Mn spring steel in the continuous cooling process is studied with the hot-press method on Gleeble3800 thermal simulation testing machine. The phase transition point and critical cooling rate are obtained according to the slope change of the curve, and then the continuous cooling transition curve (CCT curve) of 60Si2Mn spring steel is drawn. According to CCT curve, reasonable cooling control parameters of stelmor process were selected, and the process effect was verified by actual production. The results show that there is a good correspondence between CCT curve and microstructure evolution. When the cooling rate is between 1-10 ℃ / s, the structure contains ferrite and pearlite. With the increase of cooling rate, the ferrite content gradually reduce and pearlite content increased. In order to good control of surface decarburization and ferrite distribution, cold speed need to be 5-8 ℃ / s. Surface decar-burization of all spring steel specimen is within 180 μm, and ferrite tend to be uniformly distributed at the same time. Favorable conditions is provided for subsequent processing. Scientific basis and theoretical support is provided for the organization control and performance optimization of 60Si2Mn spring components which has important scientific and engineering application value for improving the service life.
Keywords: 60Si2Mn;thermal simulation;CCT curve;surface decarburization;ferrite distribution
2020, 46(2):137-142  收稿日期: 2019-04-08;收到修改稿日期: 2019-07-06
基金项目: 天津市企业科技特派员项目（18JCTPJC49500，19JCTPJC45400）
作者简介: 孙伟(1979-),男,河北秦皇岛市人,副教授,博士,主要从事金属材料质量控制及表面强化研究
参考文献
[1] 王筱冬. 高强度弹簧钢的发展现状和趋势分析[J]. 中国锰业, 2017, 35(4):104-106
[2] 霍咚梅, 肖邦国. 我国弹簧钢生产现状及发展展望[J]. 冶金经济与管理, 2015(5):8-11
[3] 孙伟, 梁云科, 刘学森. 一种弹簧钢盘条表面脱碳和铁素体分布的控制方法:CN103045935A[P]. 2013-04-17.
[4] 李红英, 赵延阔, 唐宜, 等. 6082铝合金CCT图的测定及应用[J]. 金属学报, 2010, 46(10):1237-1243
[5] 廖琳琳, 黎立璋, 严海峰, 等. 82B高碳钢静态CCT曲线及显微组织[J]. 金属热处理, 2017, 42(8):30-35
[6] 谌冬冬, 周旭东, 郭未昀. ST52-3G钢CCT曲线的测定与分析[J]. 金属热处理, 2017, 42(7):168-171
[7] 廉晓洁, 成生伟, 周杰, 等. 20Cr1Mo1V钢CCT曲线的测定与分析[J]. 热加工工艺, 2014, 43(20):28-30,33
[8] 李红英, 王法云, 曾翠婷, 等. 3Cr2Mo钢CCT曲线的测定与分析[J]. 中南大学学报(自然科学版), 2011, 42(7):1928-1933
[9] MANUEL G, LUCIA R, ESTHER E, et al. Phase trans-formation under continuous cooling conditions in medium carbon microalloyed steels[J]. Journal of Materials Science & Technology, 2014, 30(5):511-516
[10] 潘辉, 刘雅政, 崔娟, 等. 汽车用优质60Si2Mn弹簧钢控轧控冷工艺研究[J]. 轧钢, 2006(5):20-23
[11] 吴良芹. 连续冷却对60Si2Mn钢组织性能的影响[J]. 材料科学与工程学报, 2014, 32(5):712-715
[12] 王丽萍, 柳洋波, 张玮, 等. 60Si2Mn弹簧钢全脱碳的影响因素[J]. 金属热处理, 2014, 39(3):7-12