AISI440C不锈钢QPQ盐浴复合表面处理及其耐磨性研究

Study on QPQ Salt Bath Composite Surface Treatment and Wear Resistance of AISI440C Stainless Steel

对AISI440C不锈钢采用QPQ盐浴复合处理。采用SEM、显微硬度计和摩擦磨损试验机分别对处理后试样的显微组织、显微硬度、截面形貌和摩擦磨损等性能进行研究。选取4个影响QPQ试样表面性能的工艺参数(共渗温度、共渗时间、氧化温度、氧化时间),分别以平均摩擦因数和磨损量为考核指标,设计正交试验分析各工艺参数对耐磨性能的影响,并得到最佳工艺参数。通过对优化工艺处理过的QPQ试样和盐浴氮碳共渗试样进行对比分析,结果表明:获得最小磨损量的最佳工艺参数是620℃共渗1.5 h,380℃氧化40 min,最小磨损量为1.25 mg,是共渗试样的66.9%;获得最小平均摩擦因数的最佳工艺路线是580℃共渗2.5 h,300℃氧化40 min,最小摩擦因数为0.2359,是共渗试样的70.0%。

The AISI440C stainless steel was treated with QPQ salt bath.The microstructure,microhardness,cross-section morphology and friction and wear properties of the treated samples were studied by SEM,microhardness tester and friction and wear tester.Four technological parameters(infiltration temperature,infiltration time,oxidation temperature,oxidation time)affecting the surface properties of QPQ samples were selected,and the average friction coefficient and wear amount were used as the test indexes respectively.Orthogonal experiment was designed to analyze the effect of process parameters on wear resistance,and the optimal process parameters were obtained.The QPQ samples treated by the optimization process and the salt bath nitrocarburizing samples were compared and analyzed.The results show that,the optimum technological parameters for obtaining the minimum wear loss are as follows:infiltration at 620℃for 1.5 h,oxidation of 40 min at 380℃.The minimum wear amount is 1.25 mg,which is 66.9%of that of the co-permeable sample.The optimum process for obtaining the minimum average friction coefficient is that the temperature is 580℃for 2.5 h and the oxidation temperature is300℃for 40 min.The minimum friction factor is 0.2359,which is 70.0%of the co-permeability sample.