Q235钢快速碳氮共渗工艺

由于传统碳氮共渗剂存在污染环境的不足,采用气体碳氮共渗技术对Q235钢进行表面改性处理,探讨在850℃时不同的保温时间实现快速碳氮共渗处理的可行性。利用金相显微镜、扫描电镜、X射线衍射仪、显微硬度计、磨损实验机等检测分析手段对渗层的显微组织、相组成、渗层厚度以及渗层的显微硬度和耐磨性能进行了研究。结果表明：随着碳氮共渗时间的增长,显微组织越来越致密;渗层厚度增加,850℃下保温7 h时渗层的厚度达到最大,约为1400μm,显微组织也最致密。碳氮共渗层的相组成主要由碳化物（Fe3C）、氮化物（Fe3N）组成。渗层的显微硬度随着碳氮共渗时间的增加而增加,其中保温7 h时HV0.2最大达到7.97 GPa,是Q235钢的7.5倍。该工艺下渗层的耐磨性能提高显著。

Rapid carbonitriding process of Q235 steel

Aimed at the traditional nitrocarburizing agent polluting environment, this paper proposes the use of gas carbonitriding technology for the surface modification of Q235 steel and discusses the feasibility of rapid carbonitriding under different temperatures at 850 ℃. The paper introduces the investiga- tion into the microstructure, phase composition and the thickness of the layer as well as its microhardness and wear resistance by optical microscope, scanning electron microscope, X -ray diffraction diffractometer, microhardhess tester and abrasion machine. The results show that with the increase of the carboni- triding time, the microstructure become denser and denser and the layers give increased thickness . The layer is of the maximum thickness （ 1 400 μm or so） and the microstructure is the most densest as the carbonitriding time is 7 hours. The carbonitriding layers are mainly composed of carbides （Fe3 C ） and nitrides（ Fe3 N）. The microhardness of the layers shows an increase as the carbonitriding time increase, and it reaches the maximum of about 7.97 GPa （ HV0. 2 ,7.5 times of Q235 steel. The wear resistance im- proves significantly at this process.