低合金钢点蚀扩展过程中的自催化作用  

Self-catalytic Action in Pitting Propagation Process of Low Alloy Steels

作　　者：杨铁军[1] 李国明[2] 陈珊[2] 常万顺[2] 陈学群[2] 

机构地区：[1]92957部队 [2]海军工程大学理学院

出　　处：《腐蚀与防护》2010年第7期540-541,569,共3页Corrosion & Protection

摘　　要：选用了4种低合金钢,通过模拟闭塞腐蚀电池试验,考察了闭塞区溶液条件的变化对闭塞阳极腐蚀溶解速度的影响。结果表明,随着孔内FeCl2浓度增加,pH值下降,阳极腐蚀溶解的速率下降。自催化酸化作用仅是说明在闭塞电池中,溶液酸化保持了金属表面的活化状态,使孔内金属可继续溶解和水解,从而使腐蚀溶解主要集中在孔内而导致蚀孔不断扩展。其所需要的条件是孔外阴极区电位要明显高于孔内电位。Four kinds of low alloy steels had been selected and the effects of solution conditions in the occluded area on corrosion of occluded anode had been studied by means of occluded corrosion cell （OCC） testing. The results indicated that with the increase of FeCl2 concentration and decrease of pH the corrosion rate of anodic metal decreased. Self-catalytic acidification action could be explained as follows., the surface activation of the metal was maintained by the solution acidification, which made the metal dissolve and hydrolyze continuously. Consequently, the corrosion was concentrated in the pit and the pit propagated. The necessary condition was that the potential of cathode out of the pit was more positive than that of anode in side of the pit.

关 键 词：低合金钢 点蚀扩展 闭塞电池 自催化 

分 类 号：TG171[金属学及工艺—金属表面处理]