不同焊接速度下焊缝区及铝合金母材的耐蚀性研究  

Study on Corrosion Resistance of Welding Zone and Aluminum Alloy base Metal under Different Welding Speed

作　　者：栗红星 刘佳[1] 石岩[1] 蒋士春 杨喜昌[1] 刘凤德[1] 

机构地区：[1]长春理工大学机电工程学院,吉林长春130022

出　　处：《应用激光》2016年第6期696-702,共7页Applied Laser

基　　金：吉林省青年科研基金资助项目(项目编号:20140520123JH)

摘　　要：为了研究不同焊接速度下的焊缝中心及铝合金母材在海水环境中的耐蚀性,利用YAG激光-MIG电弧复合焊接设备对10 mm厚的5083铝合金进行了焊接实验;采用体显微镜、金相显微镜及电化学工作站等设备研究了不同焊接速度下5083铝合金焊缝中心及母材的微观组织、动电位极化曲线、自腐蚀电流密度及腐蚀形貌。结果表明,随着焊接速度的逐渐减小,晶粒细化能力增强;等温线清晰度增加、条数增多、宽度减小,元素烧损量逐渐降低,微气孔率呈先减小后增加的趋势。焊接速度v=0.8m/min及1.0m/min时,无钝化区的存在,抗点蚀能力较弱;焊接速度为v=0.9、1.1 m/min及1.2 m/min时,出现钝化区,抗点蚀能力较强;随焊接速度的增加,耐蚀性呈先降低后增加的趋势。焊缝区整体的耐蚀性低于母材,随焊接速度的增加,腐蚀形貌由均匀腐蚀向局部腐蚀转变且腐蚀坑逐渐增大,母材局部腐蚀最严重,较易失效。In order to study the corrosion resistance of weld center and aluminum alloy base metal in sea water environment under different welding speed. The welding experiment with 10mm thick 5083 aluminum alloy was carried out by using YAG laser-MIG are hybrid welding equipment. The mierostructure, potentiodynamic polarization curve, corrosion current density and corrosion morphology of 5083 aluminum alloy weld center and base metal under different welding speed were investigated by stereo micro- scope, metallographie microscope and electrochemical workstation equipment. The results showed that when welding speed de- creased, grain refinement ability was enhanced; the clarity and the number of isotherm were increased, the width was decreased, the element loss amount was reduced gradually, micro porosity was decreased first and increased then. When the welding speed at 0. 8 m/min and 1. 0 m/min, the anti-pitting capacity was weak. When the welding speed at 0. 9 m/min, 1. 1 m/min and 1.2 m/rain, the pitting corrosion resistance of both were better. With the decrease of welding speed, corrosion resistance was de- creased first and increased then and the whole weld corrosion resistance were better than the parent material. With the increase of welding speed, uniform corrosion turn to local corrosion and corrosion pits were extended gradually, substrate had the most seri- ous local corrosion and failed to work most easily, finally.

关 键 词：5083铝合金 激光-电弧复合焊接 动电位极化曲线 组织 耐蚀性 

分 类 号：TG406[金属学及工艺—焊接]