铸铁在流动海水中的腐蚀行为

Corrosion behavior of cast iron in flowing seawater

总结了笔者曾经进行过的3次有关铸铁在含沙流动海水中的腐蚀试验研究工作。研究结果表明:在腐蚀速率方面,铸铁与普通碳钢相似;但在腐蚀形貌方面,局部腐蚀倾向比普通碳钢明显减轻。灰铸铁添加3%的镍,不能改善其在含沙流动海水中的腐蚀行为,反而增大了局部腐蚀敏感性。镍的质量分数超过7%的铸铁在含沙流动海水中的耐蚀性能显著提高。其腐蚀率随镍含量的增加而明显降低,且没有点蚀发生。添加铬虽然能降低其腐蚀率,但局部腐蚀敏感性显著增大。

A study on the corrosion property of cast iron in flowing seawater containing sand particles was summarized on base of three tests. The results revealed that the corrosion rate of cast iron is similar to ordinary carbon steel, while according to their corrosion appearance, its tendency to local corrosion is remarkably lower than that of carbon steel. A cast iron containing 3% nickel can＇t improve its corrosion behavior in sand-containing flowing seawater; on the contrary, its sensitivity to local corrosion is increased, When the content of nickel exceeds 7%, the corrosion resistance of cast iron to sand-containing flowing seawater has an evidently increase. Its corrosion rate decreases obviously with the increase of nickel content and no pitting corrosion occurs to it. The addition of chromium also decreases its corrosion rate, but the sensitivity to local corrosion is increased notably.