钛催渗低温离子渗氮对304不锈钢组织性能的影响  

Effect of Low Temperature Plasma Nitriding with Ti Catalyst on the Microstructure and Properties of 304 Stainless Steel

作　　者：李润涛 孙斐[1,4] 汪丹丹 魏坤霞 杨卫民[1] 胡静 LI Run-tao;SUN Fei;WANG Dan-dan;WEI Kun-xia;YANG Wei-min;HU Jing(Jiangsu Key Laboratory of Materials Surface Science and Technology,Changzhou University,Jiangsu Changzhou 213164,China;National Experimental Demonstration Center for Materials Science and Engineering,Changzhou University,Jiangsu Changzhou 213164,China;Huaide College,Changzhou University,Jiangsu Jingjiang 214500,China;Institute of Modern Equipment Manufacturing,Changzhou Institute of Industry Technology,Jiangsu Changzhou 213164,China)

机构地区：[1]常州大学江苏省材料表面科学与技术重点实验室,江苏常州213164 [2]常州大学材料科学与工程国家级实验教学示范中心,江苏常州213164 [3]常州大学怀德学院,江苏靖江214500 [4]常州工业职业技术学院现代装备制造学院,江苏常州213164

出　　处：《表面技术》2023年第10期422-429,共8页Surface Technology

基　　金：国家自然科学基金(21978025,51774052);江苏省第三期优势学科建设项目(PAPD-3);江苏高校品牌专业建设工程资助项目(TAPP);材料表面科学与技术重点实验室开放课题;江苏省研究生创新基金项目(CX10292)。

摘　　要：目的 在保障304奥氏体不锈钢良好耐蚀性前提下,研发显著改善表层硬度及耐磨性的低温高效离子渗氮技术。方法 低温离子渗氮时,在试样周围均匀放置微量海绵钛,研发304奥氏体不锈钢创新钛催渗低温离子渗氮技术。采用光学显微镜、扫描电子显微镜、能谱分析仪、X射线粉末衍射仪、显微维氏硬度计、摩擦磨损测试仪,以及电化学工作站等设备分别对试样截面显微组织、物相及成分、截面显微硬度、渗层耐磨性能、耐蚀性能等渗层组织性能进行测试与分析。结果 304奥氏体不锈钢在420℃/4h钛催渗离子渗氮处理后,不仅保持了良好耐蚀性,且渗层耐蚀性比常规低温离子渗氮略有提升,同时,表面硬度与耐磨性大幅提高,表面硬度由常规离子渗氮的978HV0.025提升至1350HV0.025。磨损率由20.9μg/(N·m)降低至7.4μg/(N·m),下降了约2/3。特别有价值的是,钛催渗低温离子渗氮效率比传统离子渗氮显著提升,渗氮层厚度由常规离子渗氮的11.37μm增厚到48.32μm,即渗氮效率提高到常规离子渗氮的4倍以上。结论 本研究研发的钛催渗低温离子渗氮技术在保障304奥氏体不锈钢优良耐蚀性的同时,能够大幅度提升不锈钢表面硬度及耐磨性能,且具有显著的催渗效果。304 austenitic stainless steel has excellent corrosion resistance,but its poor hardness and wear resistance make it hard to meet the requirements in some applications,and thus surface modification is required to promote its practical applications.Plasma nitriding(PN) is a widely used surface modification technology,while higher temperature plasma nitriding results in a decrease of the corrosion resistance and lower temperature plasma nitriding(LPN) brings about quite low efficiency.In order to overcome the problems in the traditional plasma nitriding,low temperature plasma nitriding with Ti catalyst is primarily proposed in this study,and the research aims to effectively enhance the hardness and wear resistance without reduction of corrosion resistance and with high efficiency.To reach this research goal,low temperature plasma nitriding with Ti catalyst(LPNTi) was conducted at 420 ℃ for 4 h by putting some amount of sponge titanium around the samples during plasma nitriding,and the effect of plasma nitriding with Ti catalyst on the microstructure and properties of 304 austenitic stainless steel was systematically investigated by optical microscope,SEM,EDS,X-ray diffractometer(XRD),microhardness tester,friction and wear tester,electrochemical workstation,etc.The results indicated that excellent corrosion resistance of 304 austenitic stainless steel was kept and even turned to be better after plasma nitriding with Ti catalyst compared with that under traditional plasma nitriding,with the corrosion potential increasing from –320.77 mV to –316.68 mV.SEM,XRD and EDS analysis showed that LPNTi layer was mainly composed of S phase,αN and a little Ti2N with high hardness,which meant that Ti was helpful for the phase transformation of γ to α,and αN was formed due to this phase transformation.The surface hardness could be significantly enhanced from 978HV0.025 by plasma nitriding to 1350HV0.025 by plasma nitriding with Ti catalyst due to the double strengthening effect from αN and Ti2N,which was more than 6 time

关 键 词：钛催渗 离子渗氮 304奥氏体不锈钢 耐蚀性 硬度 耐磨性 

分 类 号：TG178[金属学及工艺—金属表面处理]