DC53钢的离子氮碳共渗工艺及稀土催渗研究

The technological parameter and the influence of rare earth on plasma nitrocarburzing of DC53

为了探究DC53钢的优化氮碳共渗工艺,对DC53钢在530℃不同共渗时间、NH3/CO2不同气氛比值、不同炉内气压情况下的离子氮碳共渗效果进行了研究.运用OM、XRD、SEM、EDS、显微硬度、摩擦磨损实验,对材料的显微组织、显微硬度和耐磨性进行了分析.研究表明:对于冷作模具钢DC53,10 h、NH3/CO2为15∶1、炉内气压为800～1000 Pa时,氮碳共渗效果最好;随着稀土镧(La)的加入,渗层变厚且渗层与基体更致密,表层到心部的硬度梯度更小,氮碳共渗效果更佳.

To obtain the optimal nitrocarburizing parameter of DC53 steel,the specimens have been plasma nitrocarburized at 530 ℃ for different time in a mixed gas of NH3 and CO2 with and without Rare Earth（RE）.The microstructure,microhardness and wear resistance of surface layers for the treated specimens were characterized using optical microscopy（OM）,scanning electron microscopy（SEM）,X-ray diffraction（XRD）,energy dispersive spectrometer（EDS）,microhardness and wear testers,respectively.The results show that the optimal parameter of plasma nitrocarburizing treatment for DC53 is 10 h,15∶ 1（the value of NH3/CO2） and 800~1 000 Pa.In addition,based on the optimal parameter,when lanthanum was added,the nitrocarburized layer became thicker and the gradient of hardness was smaller from the surface to the core,and the effect of plasma nitrocarburizing treatment was better.