论文部分内容阅读
用高度弥散的氮化物来取代碳化物从而提高钢的强度性能是表面及体内渗氮方法的主要目的。表面渗氮可利用化学热处理法,体内渗氮可在高压下把氮加入到液体金属中。日前已经开始研制其他有前途的方法——即利用氮作为稳定铬镍钢尤其含有低镍和锰的铬锰钢在常温下铁α—相的方法。仅仅利用氮来稳定奥氏体还需解决铬含量高的铁合金中氮在铬奥氏体中溶解度有限的问题(铬是铁素体形成元素)。当N超过一定浓度(例如对于1200℃下的Fe—18％Cr合金来说,这浓度等于0.8％N)时,再提高合金中的氮含量就不会改善其性能,因为
The main purpose of surface and in-vivo nitriding methods is to replace the carbides with highly dispersed nitrides to improve the strength properties of the steel. Surface nitriding chemical heat treatment can be used, in vivo nitriding under high pressure nitrogen can be added to the liquid metal. Other promising methods have been developed recently - the use of nitrogen as a method of stabilizing iron-α-phase at room temperature in chromium-manganese steels with stabilized nickel-chromium steels, particularly low nickel and manganese. The mere use of nitrogen to stabilize austenite also requires the solution of the limited solubility of nitrogen in chromium austenite in ferrous alloys with high chromium content (chromium is a ferrite forming element). When N exceeds a certain concentration (for example, this concentration is equal to 0.8% N for Fe-18% Cr alloy at 1200 ° C), increasing the nitrogen content in the alloy does not improve its performance because