Sb和Sn微合金化对低合金钢在模拟污染海洋大气中腐蚀行为的影响

Effect of Sb and Sn on the Corrosion Behavior of Low Alloy Steel in Simulated Polluted Marine Atmosphere

目的:探究Sn与Sb在模拟污染海洋大气环境中对低合金钢耐蚀性的影响,为我国高性能低合金钢的设计、发展与投入使用积累腐蚀数据。方法通过微合金设计和真空冶炼制备了Sn和Sb微合金化的低合金钢,并利用周浸加速实验研究了低合金钢在模拟污染海洋大气环境中的腐蚀行为。结果 5种低合金钢都是贝氏体相,Sn与Sb以固溶态的形式分布在低合金钢中。添加Sn和Sb可以减缓低合金钢在模拟污染海洋大气中的腐蚀速率,含Sn钢在腐蚀前期的蚀坑较大,扩展较快,后期发展速度变缓。添加Sn可以使锈层中生成稳定的SnO_2,促进锈层中γ-FeOOH转化为α-FeOOH,提升锈层致密性。含Sb钢的蚀坑发展速度始终慢于未添加Sn和Sb的低合金钢,Sb可以使锈层中生成稳定的产物Sb_(2)O_(3),促进锈层中γ-Fe OOH转化为Fe_(3)O_(4),提升锈层稳定性。结论添加Sn与Sb对低合金钢的微观组织结构没有影响。添加Sn与Sb可以通过改善锈层相组成的方式,提升锈层的稳定性与致密性,防止腐蚀性离子进入钢基体表面,进而提升低合金钢在模拟污染海洋大气环境中的耐蚀性。

The influence of Sn and Sb on the corrosion resistance of low-alloy steel in a simulated polluted marine atmosphere was explored to accumulate corrosion data for the design,development and use of high-performance low-alloy steel in China.Sn and Sb micro alloyed low-alloy steels were prepared through vacuum smelting,and the corrosive behavior of low-alloy steels in simulated polluted marine atmosphere was studied using accelerated immersion tests.The results showed that the five low-alloy steels are all bainite,Sn and Sb are distributed in the low-alloy steel in the form of solid solution.Adding Sn and Sb can slow down the corrosion rate of low-alloy steel in simulated polluted marine atmosphere.Sn-containing steel has larger corrosion pits in the early stage of corrosion,and the development speed slows down in the later stage of corrosion.Adding Sn can generate SnO2 in the rust layer,promote the transformation ofγ-FeOOH toα-FeOOH in the rust layer,and improve the compactness of the rust layer.The development speed of corrosion pits of Sb-containing steel is always slower than that of BS low alloy steel.Sb can generate a stable product,Sb2O3 in the rust layer,promote the transformation ofγ-FeOOH into Fe3O4 in the rust layer,and improve the stability of the rust layer.The addition of Sn and Sb has no effect on the microstructure of low alloy steel.The addition of Sn and Sb can improve the stability and compactness of the rust layer by improving the phase composition of the rust layer,and prevent corrosive ions from entering the surface of the steel substrate,thereby improving the corrosion resistance of low-alloy steel in a simulated polluted marine atmosphere.