奥氏体不锈钢表面低温离子硬化处理后的亮化处理

Brightening of austenitic stainless steel after low temperature plasma hardening

奥氏体不锈钢表面低温离子硬化处理后,其表面覆盖了一层成分复杂、结合牢固的薄膜,不仅影响了不锈钢表面的外观质量,而且还影响到其表面的耐蚀性能。对奥氏体不锈钢低温离子渗碳的试样进行电化学亮化处理,并对亮化处理前后硬化层的表面形貌、表面粗糙度、组织结构、显微硬度及耐蚀性能做了比较。结果表明,虽然亮化处理后不锈钢表面硬化层的厚度和硬度略有减小,但却能显著提高其表面的耐蚀性能,表面较亮化处理前更加光滑,Ra由0.27μm减小到0.09μm。因此,在奥氏体不锈钢表面低温离子硬化处理后再进行一次表面亮化处理是十分必要的。

The surface of austenitic stainless steel was covered with a layer of complex components thin film after low temperature plasmas hardening treatment.The film not only affects the appearance of the hardened stainless steel,but also worsen its corrosion resistance.The electrochemical brightening was carried out in order to improve the appearance of the hardened stainless steel.The outer appearance,roughness,microstructure,microhardness and corrosion resistance of the samples before and after brightening were analyzed and compared.The experimental results showed that the corrosion resistance after electrochemical brightening was much better than before,although the thickness and surface hardness of the hardened layer were reduced a little after electrochemical brightening.The surface color of the hardened layer was also restored to the original color of stainless steel,and the surface roughness Ra of the hardened layer was decreased from 0.27 μm to 0.09 μm.Therefore,the surface brightening treatment is necessary for the austenitic stainless steel after low temperature plasma hardening.