硫酸溶液中Br~－和C1~－离子对铁钝化膜破裂的影响

BREAKDOWN OF IRON PASSIVE FILM BY Br￣-AND Cl￣-IONS IN SULFURIC ACID

利用电化学方法研究了硫酸溶液中Ｂｒ－和Ｃｌ－离子对铁钝化过程的影响．相比之下对铁的钝化膜Ｂｒ－离子比Ｃｌ－离子具有更强的破坏作用．这种作用可以由卤素离子的吸附阻止无定形水合氧化铁的生成且生成可溶性络离子得到初步解释．

Bromide ions have stronger effect on the iron passive film in 0.5mol/L H2SO4 solutionthan chloride ions do. This effect can be explained by the retartation of the formation ofamorphous iron oxide by the adsorption of halide ions and forming soluble iron complexes.The critical pitting concentrations under the experiment condition are 5.0×10-4mol/L forBr- and 7. 5 X×10-4mol/L for CI-.