有关“二次钝化”现象的探讨

本文对采用恒电位法测定奥氏体不锈钢316L在NaCl溶液中的阳极极化曲线时产生“二次钝化”的现象进行了研究。在对实验进行分析的基础上,提出把Prazak的“二次钝化”理论的适用范围扩大到点蚀过程;并引用Prazak的理论对NaCl溶液中316L不锈钢的“二次钝化”现象进行了分析讨论。结论认为:“二次钝化”现象只有在特定的材料,介质和环境条件下才能产生。尽管在“二次钝化”发生时,在H_2SO_4溶液中发生的是不锈钢表面膜的过钝化溶解过程,而在NaCl溶液中发生的是点蚀过程,但产生“二次钝化”的机理是相同的。

On the Secondard Passivity in NaCl Solution

IN this paper by means of potentialstatic method secondary passivity of the stainless steel 316 in NaCl solution,which occured while measuring anodic polarization curves is discussed.The range of Prazak 's mechanism on secondary passivity is extended rom transpassive dissolution to pitting corrosion on the base of these experiments. this mechanism is then used in the discussion of secondary passivity in NaCl solution, The conclusion is that secondary passivity can only occu on certain conditions, i.e.on certain material, media and environment.The both mechanisms of the secondary passivity are like, though the process occurring in H2SO4 solution is the transpassive dissolution of the passive layer of stainless steel while the pitting corrosion of the same steel is taken place in NaCl solution.