碳钢表面加弧辉光离子镍铬共渗和渗层抗蚀性能的研究

A STUDY OF GLOW-DISCHARGE IONIZED NICKEL-CHROMIZING WITH AN ARC SOURCE AND THE CORROSION RESSISATNCE OF THE DIFFUSION LAYER OBTAINED BY THIS PROCESS

采用加弧辉光离子渗金属技术，在三种含碳量（０．１％Ｗｔ、０．４５％Ｗｔ、０．８０ｗｔ％）的碳钢试样表面进行了镍－铬共渗处理，对渗层的组织形貌、合金元素成分分布以及其相组成进行了研究，测定了经加孤辉光离子镍－铬共渗处理的试样在０．０５ｍｏｌ／ＬＨ２ＳＯ４溶液中的电位－时间曲线。结果表明，１０钢试样表面形成的镍－格共修层为单一的γ相；４５、Ｔ８钢试样表面形成的镍－铬共渗层是以γ相为基，同时存在碳化物Ｃｒ２３Ｃ６、Ｃｒ７Ｃ３。经加孤辉光离子镍－铬共渗处理后，１０、４５钢试样的表面抗蚀性能大大提高，与１８－８型不锈钢相当；Ｔ８钢试样的表面抗蚀性能没有十分明显的改善。

By using the technique of glow-discharge ionized surface alloying with an arc source, nickel-chromizing was conducted on the surface of carbon-steel samples with different carbon-content 0.1 wt%, 0.45 wt% and 0.8 wt%, designated as 10 steel, 45 steel and T8 steel, respectively. The microstructure, the elemental concentration distribution and the phases of the surface layer were studied. The corrosion resistance of the diffusion layer in 0.05 mol/L H2SO4 solution was evaluated. The results indicated that the ndcrostructure of Ni-Cr alloying layer on 10 steel was γ-phase only and on 45 and T8 steels were γ-phase based Cr23C6 and Cr7C3. The corrosion resistance of alloying layer on 10,45 steels was comparable with that of 18-8stainless steel. However, nickel-chromizing did not improve corrosion resistance for T8 steel.