感应淬火对合金铸铁组织与油摩擦性能的影响  

Effect of Induction Hardening on Microstructure and Oil Friction Properties of Alloy Cast Iron

作　　者：林少阳 刘东[1] 程超增 LIN Shao-yang;LIU Dong;CHENG Chao-zeng(School of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350116,China;Fujian Longsheng Machinery Co.,Ltd,Fuzhou 350112,China)

机构地区：[1]福州大学机械工程及自动化学院,福州350116 [2]福建龙生机械有限公司,福州350112

出　　处：《表面技术》2020年第11期236-244,共9页Surface Technology

基　　金：福州市科技计划项目(2018-G-68)。

摘　　要：目的优化感应淬火工艺,为提高合金铸铁表面硬度及耐磨性能提供理论依据。方法通过热力学计算和同步热分析法测试分析了合金铸铁相变规律,并对该材料在6 kW和8 kW功率下进行了2~8 s高频表面淬火。采用扫描电镜(SEM)、洛氏硬度计、摩擦磨损试验机,研究了不同感应淬火工艺对合金铸铁显微组织、硬度和摩擦磨损性能的影响。结果合金铸铁经感应淬火后,组织为珠光体+马氏体+石墨+磷共晶,随加热时间延长,马氏体含量增多,珠光体与磷共晶逐渐减少,直至6 kW/8 s、8 kW/6 s时消失,但是继续延长时间会产生裂纹。硬化区硬度随加热时间增长而提高,峰值为50HRC,二者的关系可用Logistic曲线描述。硬度升高会提升耐磨性,超过一定硬度后,摩擦系数在0.11波动。不同形式的裂纹可以造成磨痕宽度具有不同的变化规律。结论感应淬火可有效提升合金铸铁的表面硬度及油摩擦性能。The work aims to optimize the induction hardening process,and provide a theoretical basis for improving the surface hardness and wear resistance of alloy cast iron.The phase transformation law of alloy cast iron was analyzed by Thermo-Calc and differential scanning calorimetry(DSC),and high-frequency surface hardening was carried out to the material at a power of 6 kW and 8 kW for 2~8 s.The effects of different induction hardening processes on the microstructure,hardness and friction and wear properties of alloy cast iron were studied by scanning electron microscope(SEM),Rockwell hardness tester and friction and wear tester.After induction hardening of alloy cast iron,the microstructure was composed of pearlite,martensite,graphite and phosphorus eutectic.With the increase of heating time,the martensite content increased and pearlite and phosphorus eutectic gradually decreased until disappeared at 6 kW/8 s and 8 kW/6 s.However,the cracks occurred over time.The hardness of the hardening zone increased with the increase of heating time,and the peak value was 50 HRC.The relationship between the both could be described by the Logistic curve relationship.Increasing the hardness increased the wear resistance.After certain hardness was exceeded,the friction coefficient fluctuated at 0.11.Different forms of cracks could cause different changes in the width of the wear scar.The process of induction hardening can effectively improve the surface hardness and oil friction properties of alloy cast iron.

关 键 词：感应淬火 合金铸铁 相转变 显微组织 硬度 油摩擦 

分 类 号：TG156.33[金属学及工艺—热处理]