模拟深海压力对2种低合金钢腐蚀行为的影响

EFFECT OF HYDROSTATIC PRESSURE ON THE CORROSION BEHAVIORS OF TWO LOW ALLOY STEELS

通过腐蚀失重、电化学测试、锈层分析和微观形貌观察研究了海水压力对不同成分2种低合金钢(X和Y)腐蚀行为的影响.结果表明,X钢更易受到海水压力的影响而被加速腐蚀.深海压力均加速了2种低合金钢的职极溶解速度;压力对于X钢的氧扩散还原过程影响很小,而海水压力的增加导致Y钢阴极电流密度降低的原因是腐蚀产物直接参与了阴极还原反应.2种钢均由低压下的均匀腐蚀变为高压下的局部腐蚀,但腐蚀形貌有较大差异.高压下的X钢表面出现明显的"浅碟状"腐蚀坑,而高压下的Y钢表面出现了明显的隧道形腐蚀坑.

In this paper, the effect of hydrostatic pressure on the corrosion behaviors of two steels was investigated by weight loss test, electrochemical measurements, rust layer analysis and morphology observation in natural seawater environment with high-pressure in lab. The results showed that X steel was inclined to being corroded. With the increase of hydrostatic pressure, the corrosion resistance of two steels were deteriorated, which were attributable to the increase of the anodic reaction rate. Hydrostatic pressure had little effect on oxygen diffusion reduction process of X steel. However, the cathodic current density of Y steel under higher hydrostatic pressure decreased because the corrosion products were directly involved in cathodic reduction reaction. And with the increase of hydrostatic pressure, the morphology of two steels changed significantly and differently. Under high pressure, some shallow-dish shape localized corrosion appeared on the surface of X steel, whereas on the surface of Y steel some tunnel localized corrosion appeared.