磷元素的非平衡晶界偏聚对A690M海洋环境用钢耐海水腐蚀性能的影响

摘要

采用俄歇能谱分析了A690M海洋环境用钢在600℃回火过程中磷元素的晶界偏聚行为,结合极化曲线和腐蚀锈层的微观分析探讨了P元素晶界偏聚对A690M钢耐海水腐蚀性能的影响.研究表明:A690M钢中P元素的晶界偏聚符合空位-溶质原子复合扩散导致的非平衡偏聚机制;P的晶界偏聚含量越高,锈层内部越易形成层状磷疤坑,使板坯耐海水腐蚀性能降低.%The grain boundary segregation behavior of phosphorus in marine steel A690M during tempering treatment at 600 ℃ was analyzed by Auger electron spectroscopy.The influence of grain boundary segregation of phosphorus on corrosion resistance of A690M steel in seawater was studied by microscopic observation of corrosion rust layer and polarization curve.The results show that the phosphorus segregation at grain boundary is consistent with non-equilibrium segregation behavior caused by vacancy-solute complex diffusion.The higher the concentration of phosphorus at grain boundary,the easier the formation of lamellar corrosion pit in the rust layer,which decreases the corrosion resistance of marine steel.