316L奥氏体不锈钢低温气体渗碳后的表面特性

Surface performance of 316L austenite stainless steel after low temperature gas carburizing

提出了一种新型的奥氏体不锈钢低温气体渗碳工艺,采用该工艺对316L奥氏体不锈钢进行不同时间的渗碳处理,并对渗碳后不锈钢的表面特性进行了分析和探讨。结果表明,渗碳后试样表面晶格发生膨胀,形成了15~35μm的扩张奥氏体层,该层具有高残余压应力、高硬度、高含碳量及良好的韧性,且层中无碳化铬析出,说明该工艺兼顾了奥氏体不锈钢的表面强化与抗腐蚀性能;同时,渗碳时间对表面的强化效果影响显著,表面残余应力、硬度及碳含量等随渗碳时间延长均增加。

A new low temperature gas carburizing process for austenitic stainless steel was presented,and surface performance of 316 L austenite stainless steel carburized by the process for different carburizing time were studied. The results show that an expanded austenite layer with a depth of 15-35 μm is generated as the lattice expansion happens near the surface of the carburized specimen,and the layer shows the characteristic of high residual compressive stress,high hardness,high carbon content,good toughness and without chromium carbide precipitation,that indicates this process performs well in both surface strengthening and corrosion resistance. Meanwhile,the carburizing time has significant impact on surface strengthening effect,and the surface residual stress,hardness and carbon content of the steel increase with the carburizing time increasing.