激光淬火对高速动车组EA4T车轴钢组织和性能的影响  

Influence of laser quenching on structure and property of EA4T axle steel for high-speed EMU

作　　者：潘雪新[1] 常红 李忠文 胡小峰[1] 付鸿[1] 姜海昌[1] Pan Xuexin;Chang Hong;Li Zhongwen;Hu Xiaofeng;Fu Hong;Jiang Haichang(Institute of Metal Research,Chinese Academy of Sciences,Shenyang Liaoning 110016,China;Beijing Aerospace Propulsion Institute,Beijing 100076,China;CRRC Qingdao Sifang Co.,Ltd.,Qingdao Shandong 266111,China)

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]北京航天动力研究所,北京100076 [3]中车青岛四方机车车辆股份有限公司,山东青岛266111

出　　处：《金属热处理》2020年第5期161-165,共5页Heat Treatment of Metals

基　　金：国家重点研发计划资助(2016YFB1200501)。

摘　　要：为提高EA4T车轴钢的表面硬度和耐磨性能,采用激光淬火对调质态车轴进行表面改性。利用扫描电镜、显微硬度计、纳米压痕仪等对激光淬火层的微观组织、相变层深度和硬度进行了详细的表征。结果表明:EA4T车轴钢表面经过不同工艺激光淬火后,相变层内的淬火组织主要由细小的板条马氏体和粒状贝氏体组成,其深度根据工艺不同从100μm到800μm不等,并呈现随淬火功率的增加和扫描速度减小,相变层深度逐渐增加的趋势。淬火相变层区域内,车轴钢的显微硬度基本保持在450 HV0. 2左右,约为基体硬度的2倍,耐磨性显著提高。由于淬火道次之间搭接的原因,淬火层呈现波形分布,其中波谷马氏体含量高于波峰位置,因此其硬度明显高于波峰处。In order to improve the surface hardness and wear resistance of the EA4 T axle steel in quenched and tempered state,the surface of the axle was modified by laser quenching. The microstructure,phase transition depth and hardness of the laser quenched layer were characterized by scanning electron microscopy,microhardness tester and nano indentation meter. The results show that when the EA4 T axle surface is subjected to different laser quenching processes,the quenched structure in the phase transition layer is mainly composed of fine lath martensite and granular bainite,and the depth varies from 100 μm to 800 μm according to the process. There is a tendency that the depth of the phase change layer gradually increases as the laser quenching power increases and the scanning speed decreases. The microhardness of the quenched phase transition layer is basically maintained at about 450 HV0. 2,which is approximately twice the hardness of the matrix,so that the wear resistance of the axle steel is remarkably improved. Due to the overlapping between the quenching passes,the laser quenched layer exhibits a waveform distribution. The martensite content in the valley region is higher than that of the peak region,so that the hardness in the valley region is significantly higher than that of the peak region.

关 键 词：EA4T车轴钢 激光淬火 显微组织 硬度 

分 类 号：TG162.71[金属学及工艺—热处理]