合金元素含量对耐候钢在模拟海洋大气环境下耐蚀性的影响

Effect of Alloy Elements Content on Corrosion Resistance of Weathering Steels in Simulated Marine Atmosphere Environment

采用扫描电子显微镜和电化学交流阻抗谱研究了Q235B、SPA-H钢和2种不同镍、铬及铜含量的耐候钢在模拟海洋大气环境中的耐蚀性。结果表明:在有Cl-存在的环境中,当镍和铜含量都很低时,单独添加铬在腐蚀前期对减缓腐蚀有利,而在后期对腐蚀有促进作用;镍的质量分数小于0.25%时对耐蚀性的影响不起主导作用;电化学交流阻抗试验结果与腐蚀质量损失试验结果一致;4种钢周期浸润腐蚀48h后的锈蚀量都比较少,腐蚀192h后的锈蚀量明显增加。

The corrosion resistance of Q235B,SPA-H steel and two weathering steels with different alloys contents of Ni,Cr and Cu in simulated marine atmosphere environment were studied by scanning electron microscopy and electrochemical impedance spectroscopy.The results show that only adding Cr was beneficial for retarding corrosion in the early stage,but promoting corrosion at the late stage in the environment of Cl-when the Ni and Cu contents were very low.The effect of Ni on corrosion resistance couldn′t afford leading role when the mass fraction of Ni was less less 0.25wt%.The result of electrochemical impedance test was agreement with the result of the corrosion mass loss test.The rusting of the four steels were small after periodical immersed corrosion for 48 h,and the rusting obviously increased after corrosion for 192 h.