304L不锈钢钝化膜半导体性能研究

利用极化曲线、电容测量法和X射线光电子能谱(XPS)研究了304L不锈钢在0.5 mol/L NaHCO3溶液中所形成的钝化膜的半导体性能，同时对影响钝化膜半导体性能的因素进行了讨论.结果表明：在电位小于-0.4 V范围内，膜呈p型半导体特性；当电位处于-0.4 V至0.26 V范围内膜呈n型半导体特性.随着测试频率的降低及成膜电位的负移，Mott-Schottky曲线的斜率减小，表明膜内的杂质密度增加。氯离子的加入使得M S直线的斜率减小，增加膜内的杂质密度，容易造成点蚀的发生.XPS测试结果表明钝化膜主要由内层的铬氧化物和外层的铁氧化物组成，这与以前的研究结果相一致.

SEMICONDUCTIVE PROPERTIES OF PASSIVE FILM FORMED ON 304L STAINLESS STEEL

The semiconductive properties of passive film formed on 304L stainless steel in 0.5 mol/L NaHCO_3 solution were detected using polarization curve,capacitance measurement and X-ray photoelectron spectroscopy(XPS) measurements.In addition,the factors which affect the semi-conductive characteristic of the passive film was also discussed.The results show that the passive film exhibits p-type semiconductive characters in the potential region lower than -0.4 V,and n-type semiconductive chracters in the potential region of-0.4V to 0.26 V.With the measured frequency decreasing and film formation potential moving to much negative,the slopes of M-S plots decreases,this indicates that the impurity density in the film increases.The addition of chlorine ion in the solution can decrease the slopes of the M-S plots,and enhance the occurrence of pitting corrosion on the 304L SS.The XPS result ravels an inner layer of Cr oxide and an outer layer of Fe oxide,which is in agreement with the previous works.