工艺参数对60CrMnMo钢表面激光陶瓷合金化涂层组织与硬度的影响

Effect of Processing Parameters on Microstructure and Microhardness of Laser Alloying 60CrMnMo Steel with Ceramics

采用CO2激光器在60CrMnMo钢表面进行激光陶瓷合金化,保持激光功率、搭接率不变,研究了扫描速度和预涂层厚度对合金化层的组织与硬度的影响。利用OM、SEM、显微硬度计对激光合金化层的组织和横截面显微硬度分布进行研究。结果表明,激光合金化层与基体形成了冶金结合,随扫描速度的增加,合金化层厚度减小,合金化层硬度先提高后降低。随预涂层厚度的增加,合金化层硬度也提高。当激光功率为4000 W,搭接率为30%～40%,光斑尺寸为3～3.5 mm,预涂层厚度为30～35μm,扫描速度为2.0 m/min时,合金化层的平均显微硬度最高为1101 HV0.2,是基体材料(250 HV)的4.4倍左右。

Under the conditions of remaining the laser power,overlap ratio unchanged,a CO2 laser was adopted to make laser ceramic alloying on 60CrMnMo steel surface,and the effects of scanning speed and pre-layer thickness on the microstructure and microhardness of laser alloying layer were studied.The microstructural morphology and cross-sectional micro-hardness distribution of the alloyed coating were analyzed by OM,SEM and micro-hardness tester.The results show that the excellent metallurgical bonding is obtained between alloying laser and substrate.With the increase of scanning speed,the thickness of alloying layer decreases,while the microhardness increases then decreases.With the increase of pre-layer thickness,the microhardness also increases.When the laser power is 4000 W,overlap ratio 30%-40%,pre-layer thickness 30-35 μm,scanning speed 2.0 m/min,the microhardness of the alloyed layer is 1101 HV0.2,which is about 4.4 times as high as that of substrate.