工业纯钛和00Cr25Ni22Mo2不锈钢的缝隙腐蚀

采用在不同温度及不同介质中化学浸泡法和电化学测试方法，对工业纯钛和００Ｃｒ２５Ｎｉ２２Ｍｏ２不锈钢之间产生的缝隙腐蚀行为进行研究。结果表明：在有缝隙的情况下，００Ｃｒ２５Ｎｉ２２Ｍｏ２不锈钢在氧化性介质中的缝隙腐蚀速率明显大于在还原性介质中的缝隙腐蚀速率；工业纯钛则恰恰相反。温度对缝隙腐蚀有较大影响，随温度升高，００Ｃｒ２５Ｎｉ２２Ｍｏ２不锈钢的缝隙腐蚀加重并伴有点蚀产生；工业纯钛在１（ｍｏｌ·Ｌ－１）Ｈ２ＳＯ４溶液中，随温度升高缝隙腐蚀速率增加明显，高于８３℃伴有点蚀产生。电化学实验表明，存在缝隙情况下，在２５℃１（ｍｏｌ·Ｌ－１）Ｈ２ＳＯ４溶液中，工业纯钛的维钝电流密度小于００Ｃｒ２５Ｎｉ２２Ｍｏ２不锈钢的维钝电流密度，工业纯钛的击穿电位比００Ｃｒ２５Ｎｉ２２Ｍｏ２不锈钢的高约８００ｍＶ；而在８５℃，工业纯钛的维钝电流密度大于００Ｃｒ２５Ｎｉ２２Ｍｏ２不锈钢的，而且工业纯钛的击穿电位下降明显，两者的击穿电位十分接近

A study on crevice corrosion behavior of titanium and 00Cr25Ni22Mo2 stainless steel

The crevice corrosion behavior of titanium and 00Cr25Ni22Mo2 stainless steel is studied in the present paper. The result of test is as follows. The crevice corrosion rate of 00Cr25Ni22Mo2 in oxidative medium is much greater than that in reductive medium, but the law for titanium quite the reverse. There is much effect of temperature on the crevice corrosion rate. The crevice corrosion rate of 00Cr25Ni22Mo2 stainless steel increases with temperature, and, at the same time, pitting corrosion occurs. The crevice corrosion rate of titanium in 1 mol/L H2SO4 solution increases with temperature, and pitting corrosion happens when temperature is higher than 85. Elcectrochemical tests show: At room temperature the passive current of titanium is less than that of 00Cr25Ni22Mo2 stainless steel in 1 mol/L H2SO4 solution; the breakdown potential of titanium is 800 mV higher than that of 00Cr25Ni22Mo2. At 85 the passive current of titanium is greater than that of 00Cr25Ni22Mo2 and the breakdown potential of tita