超声冲击对钢桥焊缝耐腐蚀性能的影响

Effect of Ultrasonic Impact on Corrosion Resistance of Steel Bridge Welds

为研究超声冲击对钢桥焊缝部位耐盐雾腐蚀性能的影响,对焊缝试件进行超声冲击并进行盐雾腐蚀试验,通过金相试验分析了焊缝超声冲击后的表面微观形貌.建立焊缝盐雾腐蚀有限元模型,对比了不同冲击时间下试件的腐蚀深度、表面电位和表面电流密度.结果表明:超声冲击细化了表面晶粒尺寸,减少晶界碳化物占比,有效降低试件的腐蚀敏感性.随着超声冲击时间的增加,试件耐盐雾腐蚀性能先升高后降低.当超声冲击时间为180 s及冲击速度为3 mm^(2)/s时,试件耐盐雾腐蚀性能表现出最优.

In order to study the effect of ultrasonic impact on the salt spray corrosion resistance of steel bridge welds,weld specimens were subjected to ultrasonic impact and a salt spray corrosion test.The surface morphology of the weld after ultrasonic impact was analyzed through metallographic testing.A finite element model of weld salt spray corrosion was established,and the corrosion depth,surface potential,and surface current density of the specimens under different impact times were compared.The results show that ultrasonic impact refines the surface grain size,reduces the proportion of grain boundary carbides,and effectively decreases the corrosion sensitivity of the specimen.With the increase in ultrasonic impact time,the salt spray corrosion resistance of the specimen first increases and then decreases.When the ultrasonic impact time is 180 s and the impact velocity is 3 mm^(2)/s,the specimen exhibits optimal resistance to salt spray corrosion.