高耐候钢Q350EWR1耐蚀性能研究

Study on anti-corrosion properties of extra-weathering steel Q350EWR1

为开发新一代铁路车辆用高耐蚀型耐候钢,在1780 mm热连轧生产线上进行了高耐蚀型耐候钢Q350EWR1工业试制,并对实验钢进行了组织观察和力学性能检测分析。利用周期浸润腐蚀试验方法对高耐候钢Q350EWR1和对比钢Q345B进行了腐蚀行为研究,腐蚀溶液为0.01 mol/L的NaHSO3溶液。采用扫描电子显微镜观察实验钢和对比钢的微观形貌,利用电子探针分析腐蚀产物中的元素分布,并用X射线衍射仪对腐蚀产物进行物相分析,采用失重法进行了腐蚀速率计算。研究表明:实验钢Q350EWR1力学性能优良,满足铁标要求;随着腐蚀的进行,Q350EWR1腐蚀速率逐渐下降并趋于稳定,相对于Q345B腐蚀速率≤30%,耐腐蚀性能良好。与Q345B相比,Q350EWR1钢锈层更加致密,随着腐蚀的进行生成更多的α-FeOOH;耐蚀元素Cu、Ni、Cr在锈层中的富集大幅提高了锈层对基体的保护能力。

In order to develop a new generation of extra-weathering steel for railway vehicles,the industrial trial production of extra-weathering steel Q350EWR1 was carried out on 1780 mm hot continuous rolling line.The microstructure and mechanical properties of the experimental steel were observed and analyzed.The corrosion behavior of Q350EWR1 and Q345B steel was studied by means of periodic infiltration corrosion test.The corrosion solution was 0.01 mol/L NaHSO3.The micro-morphology of experimental and contrast steels was observed by scanning electron microscopy(SEM),the element distribution of corrosion products was analyzed by electron probe microanalysis(EPMA),the phase analysis of corrosion products was carried out by X-ray diffraction(XRD),and the corrosion rate was calculated by weight loss method.Results show that the experimental steel Q350EWR1 had excellent mechanical properties and it met the requirements of iron standard.With the corrosion proceeding,the corrosion rate of Q350EWR1 gradually decreased and tended to be stable.The corrosion rate of Q350EWR1 was less than 30%and the corrosion resistance was good.Compared with Q345B,Q350EWR1 steel had denser rust layer,and moreα-FeOOH was formed with corrosion.The enrichment of corrosion resistant elements such as Cu,Ni,and Cr in the rust layer also greatly improved the protection ability of the rust layer to the matrix.