论文部分内容阅读
利用正交试验法对20CrMnTi齿轮钢表面激光熔覆过程中激光功率、离焦量和扫描速度等工艺参数进行了优化,得到熔覆层宽度、厚度及硬度较为优良的参数组合。在此基础上,利用方差分析法研究了上述三种参数对熔覆层形貌及性能的影响情况。研究结果表明:在预置粉末厚度一定的情况下,激光功率和离焦量分别对熔覆层的宽度和高度影响程度最大。采用优化工艺参数获得的熔覆层,其摩擦系数普遍小于基体的摩擦系数;熔覆层的硬度值分布在59.4HRC至63.5HRC之间,满足20CrMnTi钢齿轮硬度的使用要求;熔覆层显微组织为均匀而细小的铁素体和珠光体,力学性能优于基体材质。
The parameters of laser power, defocusing power and scanning speed during laser cladding of 20CrMnTi gear steel were optimized by orthogonal test, and the combination of parameters with better cladding width, thickness and hardness was obtained. On this basis, the influence of the above three parameters on the morphology and properties of the cladding layer was studied by using the analysis of variance. The results show that laser power and defocus amount respectively affect the width and height of cladding layer the most. The friction coefficient of the cladding layer obtained by optimizing the process parameters is generally less than the friction coefficient of the substrate; the hardness value of the cladding layer is distributed between 59.4 HRC and 63.5 HRC, meeting the requirements of 20 CrMnTi steel gear hardness; Organized as uniform and small ferrite and pearlite, mechanical properties superior to the matrix material.