预氧化对1Cr11Ni2W2MoV不锈钢渗氮层质量的影响

Effect of Pre-Oxidation on the Quality of Nitride Layer of 1Cr11Ni2W2MoV Stainless Steel

为了研究渗氮前预氧化处理对1Cr11Ni2W2MoV材料制件渗氮层质量的影响,对调质后的试样在渗氮前进行不同预氧化处理和吹砂处理。目视观察预氧化薄膜颜色,采用金相显微镜和硬度计检测渗氮层的组织、深度、硬度和脆性等。结果表明:渗氮前对该材料在550℃下预氧化5~20 min,可以破坏不锈钢制件表面的钝化膜,使该材料制件渗层的硬度、深度及组织符合渗氮技术要求,且其渗层均匀性及渗氮速度均优于渗氮前仅进行吹砂处理的试样。

In order to study the effect of pre-oxidation treatment on the quality of the nitriding layer of stainless steel parts, quenched and tempered samples were treated with different pre-oxidation and sand blowing treatments before nitriding. The color of the preoxidized film was observed visually. The microstructure, depth, hardness, and brittleness of nitriding layer were measured by metallographic microscope and hardness tester. Results showed that the passivation film on the surface of 1 Cr11 Ni2 W2 MoV stainless steel could be destroyed if the steel was preoxidized at 550 ℃ for 5~20 min before nitriding. So the hardness, depth and structure of the nitriding layer could meet the technical requirements for nitriding if treated so. Furthermore, the uniformity and nitriding speed of the layer were better than that of the layer with only sand blowing treatment before nitriding.