轨道客车不锈钢车体电化学钝化工艺研究

文章通过显微组织、显微硬度、电化学性能表征测试,分析了不锈钢车体焊缝及热影响区的组织变化及性能差异,研究了钝化道次、移动速度等电化学钝化工艺参数对焊接接头及热影响区耐蚀性的影响规律.试验结果表明:焊接热影响区显微组织发生明显改变,显微硬度下降,表面耐蚀性明显下降,当以10 mm/s单道次钝化作业时,点蚀电位最高,耐蚀性最好,30天盐雾试验后,钝化处理表面未发现明显锈蚀.该工艺已在公司进行了推广应用,效果良好.

Electrochemical passivation for stainless steel car body of railway passenger coach

By means of characterization test of microstructure,microhardness and electrochemical performance,this paper analyzes the structural change and performance difference of welds and HAZs on car body,and studies the law of influence of electrochemical passivation parameters,including passivation sequence,moving speed,etc.,on the corrosion resistance of welding joints and heat affected zones.Test results indicate that the microstructure at welding HAZ has changed significantly,microhardness has decreased and the surface corrosion resistance has declined dramatically;when the individual pass of passivation is carried out at a pace of 10 mm/s,it could generate highest pitting potential and best corrosion resistance;after 30 days of salt spray test,no evident corrosion is found on the passivated surface.This technique has been promoted within the company and excellent results have been achieved.