W18Cr4V钢等离子相变强化的工艺与性能

Technologies and properties of plasma phase transformation strengthening layer of W18Cr4V

采用压缩氩弧等离体对高速钢W18Cr4V钢进行了表面强化,研究了工艺参数对强化层性能的影响,用金相显微镜、透射电镜和显微硬度计对等离子强化层的组织、性能进行了分析。结果表明:强化层的显微硬度随深度增加呈非线性关系,并存在一个极大值和一个极小值,最高硬度可达1 000HV0.1;扫描速度和工作电流对强化层深度有显著影响,随工作电流的增加,强化层深度增大,但表面硬度下降,随扫描速度的增加,强化层深度减小。W18Cr4V等离子强化后,强化层由板条马氏体与针状马氏体、残余奥氏体、碳化物组成,且α-Fe[111]∥γ-Fe[110],碳化物主要为M6C、MC、M23C6等,强化层组织得到显著细化。

W18Cr4V high-speed steel was strengthened by compressed arc plasma, the structure, the effect of processing parameter on properties was studied. The substructure was investigated by an optical microscope, a TEM and a microhardness tester. The results showed that the microhardness of strengthening layer appeared nonlinear relationship with depth, exiting a maximum and a minimum , the maximum microhadness was about 1 000HV0. 1. The scanning speed and electron current had a obvious influence on the thickness of strengthening layer, and the depth of strengthening layer increased with working electric current increasing, but the hardness of the top surface decreased, and the depth decreased with scanning speed increasing. Strengthening layer was consisted of mixed martensites, undissolved carbides and a small amount retained austen-ite, and there was a relationship of α- Fe [111]//γ- Fe [110], carbides referred to M6C、M23C6、MC、M2C. The structure of the strengthening layer was obviously refined.