激光硬化和渗氮复合处理W9Mo3Cr4V高速钢组织与性能

Microstructure and Properties of W9Mo3Cr4V High Speed Steel Treated by Laser Hardening and Nitriding

采用激光硬化与渗氮复合表面改性技术,对W9Mo3Cr4V高速钢表面进行了强化处理。利用X射线衍射仪、扫描电子显微镜、电子探针、显微硬度计和摩擦磨损试验机,分别对复合处理试样的相组成、微观组织、成分、显微硬度和耐磨性进行了分析。研究结果表明,复合处理表面改性层主要是回火马氏体、残余奥氏体、Fe3N、Cr7C3、M2C型碳化物所构成。由于激光硬化的晶粒细化作用,以及大量位错、孪晶、空位等微观缺陷的产生,致使氮化层的深度得到明显提高。与单一的激光硬化和渗氮工艺相比,复合处理工艺有效地提高了高速钢的硬度和耐磨性能。

W9Mo3Cr4V high speed steel is treated by composite technology of laser hardening and nitriding. The microstructure and properties of the sample after the composite treatment are investigated by means of X-ray diffraction, scanning electron microscopy, electron probe micro-analyzer, Vickers hardness tester, and friction wear testing machine. The results show that the surface modification layer consists of tempered martensite, retained austenite, Fe3 N, Cr7 C3 , and M2 C phases. Laser hardening obviously increases the depth of the nitrided layer, as a result of grain refinement, as well as production of high concentration microscopic defects. Compared to laser hardening and nitriding technologies, respectively, the composite treatment technology can effectively increase the hardness and wear resistance of the high speed steel.