【作者】 李铸国； 黄坚； 张轲； 张悦； 王亚平； 芮佳宁；

【Author】 LI Zhu-guo;HUANG Jian;ZHANG Ke;ZHANG Yue;WANG Ya-ping;RUI Jia-ning;School of Materials Science and Engineering,Shanghai Jiaotong University;Shanghai Key Laboratory of Materials Laser Processing and Modification;Yanfeng Visteon Automotive Tooling Co.,Ltd.;

【机构】 上海交通大学材料科学与工程学院； 上海市激光制造与材料改性重点实验室； 延锋伟世通汽车模具有限公司；

【摘要】 采用高功率半导体激光对42CrMo4钢表面进行淬火硬化实验,通过实时检测和反馈表面温度场以及调整激光器输出功率对加热峰值温度进行了闭环过程监控,研究了基于温度场监控的工艺控制方法对表面硬化层形貌、组织和性能的影响。结果表明,基于温度场监控的工艺控制方法可在扫描方向获得硬化深度一致的硬化层;当加热峰值温度一定时,随着扫描速度的降低,激光输出功率降低,硬化层深度增加;在加热峰值温度为1350 OC、扫描速度为1.3 m/min时,可获得宽度为9mm、深度为1mm的硬化层,所需激光能量约为1.25千瓦,硬化层的组织主要为针状马氏体,显微硬度达到HV 650。更多还原

【Abstract】 Experiments on surface hardening of 42CrMo4 plates were carried out by using high power diode laser.Temperature fields of hardening zone were monitored in real time and then fed back to adjust the laser power,resulting in a close-loop control of the heating temperature.The effects of this technical approach on the morphology,microstructure and property of the hardened zone were investigated.The results show that 1) the technical approach of close-loop control of the peak temperature makes it possible to obtain an identical depth of hardened zone along the whole hardened path;2) when the peak temperatures are same,the laser power decreases and the depth of hardened zone increases upon decreasing the scan speed of the laser beam;and 3) at a peak temperature of 1350 OC and a scanning speed of 1.3 m/min,a laser power of about 1.25 KW is possible to produce a hardened zone with 9 mm in width and 1 mm in depth;the hardened zone consists of fine acicular martensite and its hardness reaches at about HV 650.更多还原