高强低合金钢焊接接头在海水中的初期腐蚀行为

Initial Corrosion Behavior of High Strength Low Alloy Steel Welded Joint in Seawater

通过电化学方法和表面分析技术,研究了高强低合金钢焊接接头在海水中的初期腐蚀行为。结果表明:浸泡前母材区的初始电位较低,腐蚀倾向最大,浸泡后母材区电位波动最大;该焊接接头在初期腐蚀呈现阳极溶解速率由高向低转变的特征,其中母材区阳极溶解电流密度最大;焊接接头在海水中的初期腐蚀以全面腐蚀和点蚀两种形式发展,腐蚀产物主要成分为α-Fe_(2)O_(3),α-FeOOH和γ-FeOOH。在海水中浸泡初期,焊接接头各区域耐蚀性从低到高排序为母材区、热影响区、焊缝区。

The initial corrosion behavior of high strength low alloy steel welded joint in seawater was studied by electrochemical methods and surface analysis.The results show that the base metal zone with low initial potential displayed the highest corrosion tendency before immersion.After immersion in seawater,the surface potential of base metal zone showed the largest fluctuation.The welded joint exhibited a transition of anodic dissolution from high speed to low speed during the initial corrosion,and the base metal zone of the joint had the highest current density.The initial corrosion process of welded joint developed in two forms of general corrosion and pitting corrosion in seawater.The composition of the corrosion products was mainly composed ofα-Fe_(2)O_(3),α-FeOOH andγ-FeOOH.The corrosion resistance of different zones of the high strength low alloy steel welded joint in seawater increased in order of base metal zone,heat affected zone,weld zone,at the initial stage of immersion in seawater.