罐装法氯化铵催化40Cr钢渗氮组织与耐磨性能

Microstructure and wear-resisting property of 40Cr steel of ammonium chloride catalytic nitriding using seal pot method

为实现渗氮工艺的低成本、快速性,以NH4Cl为催化剂,采用罐装法对40Cr钢表面进行渗氮处理。利用金相显微镜、X射线衍射仪、显微硬度计和摩擦磨损实验机对渗氮层的显微组织、显微硬度和耐磨性能进行研究。结果表明:渗氮层组织主要由Fe相和Fe3N相组成。随着NH4Cl加入比例的增大,渗氮层厚度、显微硬度和耐磨性能也呈增大趋势。当NH4Cl的质量分数为4.5%时,白亮层厚度达2.5μm,硬度为8.89 GPa,失重量为6.91 mg。氯化氨能明显增加渗氮层厚度,改善渗层耐磨性能,是一种优良的催渗剂。

Aimed at probing into the feasibility of faster nitriding at a lower cost by using the ammonium chloride catalyst,this paper describes the surface nitriding treatment of 40Cr steel by the seal pot method.The research on microstructure,the microhardness and the wear-resisting property of the nitriding layer of 40Cr steel using the optical microscope,X-ray diffractermeter,the microhardness tester,and the friction wear testing machine shows that the nitriding layer consists mainly of Fe and Fe3N phase.The increasing proportion of NH4Cl addition tends to yield increasing thickness of the nitriding layer and microhardness and the wear-resisting property.The presence of 4.5% NH4Cl catalytic agent affords the thickness of the white layer of up to 2.5 μm,the microhardness of 8.89 GPa and the loss weight of 6.91 mg.NH4Cl,capable of a significant increase in the thickness of the nitriding layer and improvement in its wear-resisting property,behaves as a kind of excellent catalyst.