Q235焊接接头的缝隙腐蚀行为  

CREVICE CORROSION BEHAVIORS OF Q235 WELD JOINT

作　　者：喻巧红 刘超[1] 庞晓露[1] 刘泉林[1] 高克玮[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《金属学报》2014年第11期1319-1326,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目51271024~~

摘　　要：针对我国特定地质处置环境,采用浸泡方法研究了高放废物包装容器候选材料Q235低碳钢焊接接头在模拟地下水溶液中的缝隙腐蚀行为,考察了温度以及溶液中氧浓度的影响.利用OM观察了焊接接头不同区域的显微组织,利用SEM和表面轮廓仪分析了不同区域的腐蚀行为,并采用电化学方法测量了各个区域的开路电位.结果表明,升高温度和氧含量能够促进缝隙腐蚀过程,并对缝隙内外的腐蚀过程均有促进作用.熔合区组织为大量聚集的铁素体组织,腐蚀最严重,其次是具有粗大魏氏体组织的焊缝区,母材区和热影响区组织相对均匀细小,腐蚀相对较轻.As a candidate package material for high level radiation waste disposal, the crevice corrosion behavior of Q235 low carbon steel weld joint was investigated in a solution simulated to the groundwater in the northwest part of China. The influences of temperature and oxygen content were evaluated. The microstructure of the weld joint was observed by OM, and SEM and surface profile were employed to analyze the crevice corrosion behavior of the weld joint. Open circuit potential of different regions of the weld joint was measured by electrochemical method. Experimental results indicated that the increases of temperature and oxygen content could promote the occurrence of crevice corrosion, and facilitate the corrosion processes both inside and outside the crevice. Fusion zone with a microstructure of clustered ferrite was the most severe corroded area in the weld joint, followed by weld metal, which was characterized by a coarse widmanstaetten structure. The microstructures of base metal and heat affected zone were fine and homogeneous, so these two regions underwent slighter corrosion.

关 键 词：Q235焊接接头 缝隙腐蚀 温度 氧 显微组织 

分 类 号：TG172.3[金属学及工艺—金属表面处理]