可控离子渗入工艺对304不锈钢组织和耐磨抗蚀性能的影响

Effect of programmable ion permeation process on microstructure and anti-wear anti-corrosion properties of 304 stainless steel

采用正交试验法研究了可控离子渗入(PIP)技术离子渗入过程中主要工艺参数:温度、时间和有效成分对304不锈钢(0Cr18Ni9)显微组织和性能的影响,并得出最优工艺参数。利用光学显微镜、X射线衍射仪、扫描电镜(SEM)、摩擦磨损试验机和电化学工作站研究了PIP处理改性层的显微组织、物相组成、磨损形貌和电化学极化曲线。结果表明:304不锈钢经PIP最优工艺(430℃×4 h×40%)处理后,形成过饱和的S单一物相,无CrN相析出;PIP渗层组织硬度达到了994 HV0. 1,磨损机制由PIP处理前的粘着磨损变为处理后的磨粒磨损,耐磨性能大幅提高;PIP处理后腐蚀电位Ecorr由-0. 183 V提高至-0. 162 V,击穿电压Ep由-0. 025 V提高至0. 10 V。上述结果表明:PIP处理形成的单一S相,能提高不锈钢表面耐磨性能,同时也增加了不锈钢的耐点蚀性能。

Effect of programmable ion permeation(PIP)process parameters(temperature,time and effective infiltration agent concentration)on the microstructure and properties of 304 stainless steel(0Cr18Ni9)were studied by using the orthogonal test method,and the optimal process parameters were obtained.The microstructure,phase composition,wear morphology and electrochemical polarization curves of the PIP treated modified layer were studied by means of optical microscope,X-ray diffractometer(XRD),scanning electron microscope(SEM),friction and wear tester and electrochemical workstation.The results show that,after treated by the optimal PIP process(430℃×4 h×40%),the supersaturated S single phase is formed in the 304 stainless steel and no CrN phase is precipitated,the hardness of PIP layer reaches 994 HV0.1;the wear mechanism changes from adhesive wear to abrasive wear,the wear resistance is significantly improved;the corrosion potential Ecorr increases from-0.183 V to-0.162 V,and the breakdown voltage Ep increases from-0.025 V to 0.10 V.The above results indicate that the single S phase formed by PIP treatment can not only improve the wear resistance of the stainless steel surface,but also increase the pitting resistance of the stainless steel.