SiCr系弹簧钢热处理钢丝奥氏体晶粒度检验方法  

Test method of austenite grain size of SiCr spring steel heat-treated wire

作　　者：金涛 孙逢源 王海华 张剑锋 郑晓伟 JIN Tao;SUN Fengyuan;WANG Haihua;ZHANG Jianfeng;ZHENG Xiaowei(Special Steel Institute/Wire Institute,Xingcheng Special Steel Works Co.,Ltd.,Jiangyin 214429,China)

机构地区：[1]兴澄特种钢铁有限公司特钢研究院线材所,江苏江阴214429

出　　处：《物理测试》2023年第4期15-19,共5页Physics Examination and Testing

摘　　要：试样采用SiCr系弹簧钢热处理钢丝,采用直接淬硬法和氧化法检验奥氏体晶粒度。结果表明,直接淬硬法检验弹簧钢热处理钢丝奥氏体晶粒度,用4%硝酸酒精溶液浸蚀,无法抑制马氏体组织的显现,导致在显微镜下观察奥氏体晶界模糊不清晰,不能准确判断其奥氏体晶粒度级别;氧化法检验的弹簧钢热处理钢丝的奥氏体晶界在显微镜下清晰可见,通过测定的相变温度和相变动力曲线进行加热温度的调整,并根据试样大小确定保温时间,SiCr系弹簧钢最佳的热处理工艺为810℃加热保温30 min,可接近真实的弹簧钢热处理钢丝奥氏体晶粒度,从而指导弹簧拉丝厂进行热处理技术的攻关,改善弹簧钢钢丝的性能。SiCr spring steel heat-treated wire was used as the sample.The austenite grain size was tested by direct hardening method and oxidation method.In the direct hardening method for the test of austenite grain size of SiCr spring steel heat-treated wire,the sample was etched with 4%nitric acid alcohol solution.The results showed that the appearance of martensite could not be restrained,leading to the unclear austenite grain boundary when observed under a microscope.As a result,the grade of austenite grain size could not be accurately determined.For the oxidation method,the austenite grain boundary of spring steel heat-treated wire was clear under the microscope.The heating temperature was adjusted by measuring the phase transition temperature and phase transition kinetic curve.The holding time of temperature was determined according to the sample size.The optimal heat treatment process for SiCr spring steel was heating at 810℃for 30 min,and it could be close to the austenitic grain size in real spring steel heat-treated wire.This study could guide the technological breakthrough of heat treatment in spring wire drawing plant to improve the performance of spring steel wire.

关 键 词：弹簧钢 奥氏体晶粒度 直接淬硬法 氧化法 

分 类 号：TG161[金属学及工艺—热处理] TG142.15[金属学及工艺—金属学]