用深度轧制方法获得了块体纳米304不锈钢材料.通过动电位极化曲线和Mott-Schottky分析等电化学测试手段,探讨了轧制纳米块体304不锈钢与普通304不锈钢(304ss)在0.05mol/L H2SO4+0.05mol/L NaCl溶液中钝化膜的耐Cl^-侵蚀性能.研究表明,深度轧制使304不锈钢组织内部形成高密度纳米尺度孪晶;纳米化表面可以形成致密的钝化膜,使其耐Cl^-侵蚀能力提高.对钝化膜半导体性能分析结果表明,轧制纳米块体不锈钢钝化膜中的载流子密度有所下降,这在一定程度上抑制了钝化膜的电化学反应历程,从而进一步提高了钝化膜的化学稳定性.
Nanocrystallized bulk 304 stainless steel(304ss) was prepared by the severe rolling equipment. X- ray diffraction (XRD), optical micrograph and transmission electron microscopy (TEM) were used to characterize micro - structure of materials. Meanwhile, using different electrochemical methods, such as polarization curves, electrochemical impedance spectrum ( EIS), and Mott - Schottky analysis, the effect of chloride ion attack on the passive film was investigated in 0.05 mol/L H2SO4 +0.05 mol/L NaC1 aqueous solution. The passive film formed on surface of nanocrystallized bulk 304ss was more compact and more protective to chloride ion than that formed on its counterpart alloy. Meanwhile, the donor carrier density decreased in the passive film, which restrains the passive film electrochemical reaction and improves the passive film stability. Therefore, the nanocrystallized bulk 304ss was more protective against chloride ion attacking in 0.05 mol/L H2SO4 +0.05 mol/L NaCl aqueous solution.