一种高磷耐候钢的耐腐蚀性能试验研究

Experimental Study on the Corrosion Resistance of a High-phosphorus Weathering Steel

利用实验室加速腐蚀试验方法,对高磷耐候钢与Q345普通低合金钢在不同腐蚀时间后的年腐蚀速率及试样锈层形貌、腐蚀产物进行了对比分析,结果表明:两种试验钢试样基体表面均由最先形成的黑色氧化物Fe_3O_4非保护性结构继续氧化成为褐色Fe_2O_3,再继续生成非稳态的γ-FeOOH,并进一步向最终的稳定锈层组成物α-FeOOH转变。高磷耐候钢中Cu、P、Cr、Ni等耐蚀性合金元素在锈层的持续富集促使锈层中α-FeOOH的形成和含量增加,其锈层中的α-FeOOH含量在不同腐蚀周期内均比Q345低合金钢中的含量高;高磷耐候钢的年腐蚀速率随腐蚀时间延长基本稳定且呈下降趋势,低于Q345普通低合金钢。

Using the laboratory accelerated corrosion test method,the contrastive analysis on the annual corrosion rates of high-phosphorus weathering steel and Q345 low-alloy steel and the morphology and corrosion products of rust layer on the surface of their specimens were carried out.The results showed that,on the surface of two kinds of test steel specimens,the black oxide of Fe3O4 formed in the earliest period continued to be oxidized to the brown Fe2O3,and then continued to generate the unsteady γ-FeOOH,further to transform toward the final stable composition rust layer of α-FeOOH.And with the extension of corrosion time,the alloy elements with corrosion resistance,including Cu,P,Cr and Ni,would continue to enrichment,which could bring the formation and increase in content of α-FeOOH in the rust layer,and thus the content of α-FeOOH in the rust layer of high-phosphorus weathering steel after different corrosion times was all higher than the content of Q345 low-alloy steel,and at the same time,the annual corrosion rate of high-phosphorus weathering steel was lower than that of Q345 low-alloy steel and showed a basically stable and slight downward trend.