摘要
采用光学显微镜(OM)、扫描电镜(SEM)和材料表面综合性能测试仪等研究了回火温度对NM500低合金高强度耐磨钢的显微组织、力学性能和耐磨性能的影响。结果表明,NM500钢经淬火+回火处理后得到典型的回火马氏体组织,回火温度的升高使得固溶在马氏体板条中的过饱和碳原子逐渐析出,而碳化物聚集长大导致钢的硬度和低温冲击性能明显下降。NM500钢在200℃回火后的硬度和-20℃低温冲击吸收能量分别为513 HBW和44.40 J,耐磨性能最佳。低温回火(200、250℃)时少量细小弥散的过饱和碳原子析出改善了钢的耐磨性,300℃及以上回火时聚集粗化的短棒状渗碳体会降低基体的硬度,导致钢的耐磨性不断降低,磨损机制由磨粒磨损向粘着磨损转变。
Effect of tempering temperature on microstructure, mechanical properties and wear resistance of NM500 low alloy high strength wear-resistant steel was studied by means of optical microscope(OM), scanning electron microscope(SEM) and material surface comprehensive performance tester. The results show that the typical tempered martensite structure is obtained in the NM500 steel after quenching and tempering. With the increase of tempering temperature, supersaturated carbon atoms in martensite laths are gradually precipitated, the hardness and low temperature impact absorbed energy of the NM500 steel decrease obviously after the carbides grow up. The hardness and impact absorbed energy at-20 ℃ of the NM500 steel after tempering at 200 ℃ are 513 HBW and 44.40 J, respectively, and the wear resistance is the best. When tempering at low temperature(200 and 250 ℃), a small amount of fine dispersed supersaturated carbon atoms precipitate, which improves the wear resistance of the steel. When tempering at 300 ℃ and above, the aggregated coarsened short rod cementite will reduce the hardness of the matrix, resulting in a continuous decrease in the wear resistance of the steel. The wear mechanism changes from abrasive wear to adhesive wear.
作者
朱震宇
吴志方
吴润
Zhu Zhenyu;Wu Zhifang;Wu Run(Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan Hubei 430081,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第10期154-159,共6页
Heat Treatment of Metals
关键词
NM500耐磨钢
回火温度
显微组织
力学性能
干摩擦性能
NM500 wear-resistant steel
tempering temperature
microstructure
mechanical properties
dry friction property
