高强缆索钢的盐浴等温淬火工艺  

Salt bath isothermal quenching process of high strength cable steel

作　　者：王雷 陆超 李月云 张宇 Wang Lei;Lu Chao;Li Yueyun;Zhang Yu(Institute of Research of Iron&Steel,Sha-steel Jiangsu Province,Zhangjiagang Jiangsu 215625,China)

机构地区：[1]江苏省沙钢钢铁研究院有限公司,江苏张家港215625

出　　处：《金属热处理》2024年第10期52-58,共7页Heat Treatment of Metals

摘　　要：为探究高碳钢盘条在盐浴等温淬火过程中的相变规律,以92Si钢盘条为研究对象,测定了高温盘条浸入熔盐后的冷却曲线,使用Deform软件计算了样品与熔盐之间的对流换热系数,进而分析了盘条在熔盐中的冷却规律,研究了加热温度与熔盐温度对盘条组织与力学性能的影响。结果表明:92Si钢盘条在等温淬火处理时,由于相变热很难被快速传导走,导致盘条在熔盐中发生连续变温相变;通过适当降低熔盐温度可提升熔盐的换热能力,提高盘条的冷却效果。盘条盐浴等温淬火后的抗拉强度主要由熔盐温度决定,在珠光体相变温度范围内,熔盐温度越低,相变后珠光体片层间距越小,抗拉强度越高;盘条塑性主要由相变前的加热条件决定,随着加热温度提高,原奥氏体晶粒尺寸变大,相变后盘条中的珠光体团与Block尺寸增加,盘条断面收缩率降低。In order to investigate the phase transformation law of high carbon steel wire rod during isothermal quenching in salt bath,the cooling curves of high temperature wire rod after entering molten salt was measured by taking 92Si steel as the research object,and the convective heat transfer coefficient between the wire rod and molten salt was calculated by using Deform software,and then the cooling law of wire rod in molten salt was analyzed.In addition,the effects of heating temperature and salt bath isothermal temperature on microstructure and mechanical properties of the wire were studied.The results show that the phase transformation heat is difficult to be transferred quickly during isothermal quenching,which leads to the continuous non-isotermal phase transformation of wire rod in molten salt.The heat transfer capacity of the molten salt can be improved by reducing molten salt temperature,and then the cooling effect of the wire rod can be improved.The tensile strength of the wire rod after salt bath isothermal quenching is mainly determined by the molten salt temperature,and reducing the molten salt temperature in the pearlite transformation temperature range leads to smaller pearlite lamellar spacing and higher tensile strength.The plasticity of the wire rod is mainly determined by the heating conditions before phase transformation.With the increase of heating temperature,the prior austenite grain size becomes larger,the size of pearlite colony and block in the wire rod after phase transformation increases,and the percentage reduction of area of the wire rod decreases.

关 键 词：盐浴 等温淬火 相变温度 抗拉强度 断面收缩率 

分 类 号：TG156.5[金属学及工艺—热处理]