建筑结构用耐候钢Q460在模拟南海海洋大气环境下的腐蚀性能

CORROSION PERFORMANCE OF Q460 WEATHERING STEEL USED FOR BUILDING STRUCTURE IN SIMULATED ATMOSPHERE OF SOUTH CHINA SEA

对添加了Cr、Ni、Cu、Mo耐蚀元素的Q460 MPa建筑用传统高强钢在模拟大气环境下进行干湿循环加速腐蚀试验,研究其在高温高湿南海海洋大气下的腐蚀行为及耐蚀机理,并对干湿循环后的样品进行形貌表征、成分分析和电化学过程分析。结果表明:Cr相对含量最多的Q460-1钢腐蚀速率最慢,耐大气腐蚀性能最好;未添加Cr、Ni、Cu、Mo的Q460钢的腐蚀速率最快,Ni含量略多的Q460-2钢腐蚀速率次之。合金元素能提高钢耐蚀性的根本原因:一方面是含有耐蚀合金元素的稳定氧化物在锈层中的均匀分布;另一方面是合金元素的添加促进了锈层中具有保护性的腐蚀产物α-FeOOH的生成。

In order to study the corrosion behavior and corrosion resistance mechanism of Q460 MPa traditional high strength steel added with Cr,Ni,Cu and Mo in high temperature and high humidity atmosphere of South China Sea,the dry wet cycle accelerated corrosion test was carried out in simulated atmospheric environment.The samples were characterized by morphology,chemical composition and electrochemical process.The results show that the Q460-1 steel with the largest relative content of Cr has the slowest corrosion rate and the best atmospheric corrosion resistance;the corrosion rate of Q460 steel without Cr,Ni,Cu,and Mo is the fastest;and the corrosion rate of Q460-2 steel with slightly more Ni content is the second.The fundamental reason why alloying elements can improve the corrosion resistance of steel is the uniform distribution of stable oxides containing corrosion-resistant alloying elements in the rust layer.On the other hand,the addition of alloying elements promotes the formation of the protective corrosion productα-FeOOH in the rust layer.