模拟流动海水腐蚀环境下含Cr钢与C钢的锈层研究

Rust Layer Formed on Cr-containing Steel and Carbon Steel in Flow Environment of Artificial Marine Water

采用人工海水对含有相同基本成分的C钢和添加了0.95%Cr元素的Cr钢进行120h的流动冲刷腐蚀试验。利用SEM和XRD等方法研究了Cr元素对普碳钢锈层的形貌、物相构成及相对含量的影响。结果表明,经冲刷腐蚀以后,含Cr钢的腐蚀质量损失小于C钢的。对两种钢的锈层分析表明,两种实验钢的锈层均出现分层现象,普碳钢外锈层疏松多孔,而含Cr钢的外锈层呈块状,致密性明显优于碳钢,内锈层亦是如此。两种钢的外锈层均由Fe3O4、α-FeOOH和γ-FeOOH等物相构成;C钢的内锈层由Fe3O4构成,Cr元素在含Cr钢锈层中的富集没有改变外锈层的物相类型,但内锈层则由Fe3O4转变为β-FeOOH。

The corrosion of Fe-0.95Cr alloy and carbon steel exposed for 120 h in flow environment of artificial marine water was compared.The effects of Cr content on the morphology,phase composition and phase content were examined by SEM and XRD.The results show that both of the two rust layers of carbon steel and Cr-containing steel are composed of two layers.The outer rust layer formed on carbon steel is loosen,while the outer rust layer formed on Cr-containing steel is compacter.The inner rust layers also has the same phenomenon.The outer rust layer formed on carbon steel is composed of Fe3O4,α-FeOOH and γ-FeOOH,the inner rust layer of carbon steel is only Fe3O4.The concentration of Cr in the rust layer forming on the Cr-containing steel alloy does not change the type of outer rust layer,but it causes the inner rust layer transforming from Fe3O4 into β-FeOOH.