Cr含量对耐候钢耐候性的影响

Effect of Chromium Content of Weather-Resisting Steel on Weathering Resistance

通过周浸腐蚀试验、电化学测量、锈层微观分析等方法研究了不同Cr含量耐候钢在模拟工业大气环境中的腐蚀行为。结果表明:随着耐候钢Cr含量增加,Cr在锈层中明显富集,促使锈层更加致密,减小了阳极溶解反应电流密度;其表面锈层的电阻Rr及反应电阻Rt均呈增大趋势,锈层的腐蚀电位正移,自腐蚀电流密度减小,极化曲线的阳极部分明显受到了阻碍,从而提高了耐候钢的耐蚀性。

The corrosion behavior o weather-resisting steel with different contents of Cr in simulated industry atmosphere was evaluated by making use of periodic im mersion tests,electrochemical measurements,and microanalysi of rusted layer. Results indicated that,with the increase in C content of weather-resisting steel,Cr was obviously enriched in the rusted layer,and the rusted layer tended to become more dense,while the current density of cathode dissolution reaction tended to decline therewith. In the meantime,both the resistanc of the surface rusted layer and the reaction resistance tended t rise with increasing Cr content,and the corrosion potential of the rusted layer tended to shift positively. Moreover,the corrosion current density tended to decline,and the anodic regime of the polarization curve was obviously hindered therewith,correspond ing to improved corrosion resistance of the weather- resisting steel.