深冷处理对碳钢表面Mo-Cr合金层摩擦性能的影响

介绍了一种在Q235钢表面进行等离子合金化及热处理工艺,获得表面高性能强化层的技术方法.通过该技术方法的处理,使Q235钢表面含有Mo,Cr,C合金元素,成分达到或接近冶金高速钢.该工艺技术的基本原理是在真空容器中,利用辉光放电的溅射现象,首先在Q235钢表面渗入合金元素Mo,Cr,表面含量分别达到12%(质量分数,下同)和4%左右,随后进行超饱和渗碳,使表面含碳量达到2.0%以上,合金化层成分接近钼系高速钢.合金层中的碳化物细小、均匀、弥散,无粗大的共晶莱氏体组织.Q235钢表面合金化后分别采用淬火 低温回火,淬火 2h深冷处理 低温回火两种工艺.结果发现,经深冷处理的试样表面硬度达到1600HV,明显高于未经过深冷处理试样的表面硬度.摩擦磨损实验表明,经深冷处理试样的滑动摩擦系数较未经深冷处理试样的要小,经深冷处理试样的耐磨性是未经深冷处理的1.6倍.

Effect of Cryogenic Treating on Wear Resistance of Plasma Alloying Surface Layer of Q235 Steel

Plasma alloying and heat treatment technology were introduced to modify the content of the surface layer of Q235 steel sample.Using the technology,alloying elements Mo,Cr,C can be obtained in the surface layer of Q235 steel sample.The content is about up to that of high speed steels.The fundamental principle is that alloying elements Mo,Cr are penetrated into the Q235 steel samples by glow discharge sputtering so that the Mo,Cr in alloyed layer is about 12%(mass fraction) and 4% respectively in the Q235 steel surface layer and so alloyed layer is similar to molybdenum high speed steel with surface carburized up to 2.0%.Large eutectic ledeburite is not found.After hardening + low tempering and hardening+cryogenic treatment 2h+low tempering,it is found that the hardness of cryogenic treatment surface is up to 1600HV which much higher than that of other technology.The abrasion test results indicate that the number of friction coefficient of the latter is lower than that of the former and wearability of the latter increases by a factor of 1.6 comparing to that of the former.