论文部分内容阅读
通过对50Cr Mo4(德国)滚珠丝杠钢表面感应淬火,低温下回火处理,分析了淬火硬化层的物相、显微组织、断口形态、显微硬度等,计算了淬硬层残留奥氏体含量,探讨了在往复直线干摩擦条件下及不同载荷条件下的磨损特性。结果表明,感应淬火处理后,50Cr Mo4钢淬硬层的硬度由250 HV提高到700 HV,淬硬层组织主要为细小的回火马氏体,从表层到心部的断口形态分别为沿晶断裂、韧窝+穿晶混合断裂,韧性断裂。随着磨损载荷的增大,材料的摩擦系数逐渐降低。低载荷下材料磨损表面存在明显的犁沟,磨损机制为磨粒磨损;随着载荷的增加,磨损表面开始出现剥落凹坑,且剥落凹坑的数量增多;高载荷下磨损表面存在犁沟和明显的剥落凹坑,磨损机制为磨粒磨损和剥层磨损。
Through the induction hardening on the surface of 50Cr Mo4 (Germany) ball screw steel and the tempering treatment at low temperature, the phase, microstructure, fracture morphology and microhardness of the hardened layer were analyzed. Body content, the wear characteristics of reciprocating linear dry friction under different load conditions were discussed. The results show that the hardness of hardened layer of 50Cr Mo4 steel increases from 250 HV to 700 HV after inductive quenching, and the microstructure of hardened layer is mainly small tempered martensite. The fracture morphology from the surface to the heart is Fracture, dimple + transcrystalline mixed fracture, ductile fracture. As the wear load increases, the friction coefficient of the material gradually decreases. Under the low load, there is obvious furrow on the surface of the material, and the wear mechanism is abrasive wear. With the increase of the load, the surface of the worn surface begins to peel off and the number of peeled pits increases; the furrow and Clear peel pits, wear mechanism for the abrasive wear and peeling wear.