磷对低碳钢坑孔腐蚀扩展的影响  

Effect of phosphorus on the pitting propagation of low carbon steels

作　　者：张恒[1,2] 常万顺[1] 王小燕[3] 曹国良[1] 陈学群[1] 

机构地区：[1]海军工程大学理学院 [2]中国人民解放军92601部队 [3]马鞍山钢铁股份有限公司

出　　处：《北京科技大学学报》2011年第4期423-427,共5页Journal of University of Science and Technology Beijing

摘　　要：采用特殊设计的闭塞腐蚀电池实验,并利用能量色散谱仪分析腐蚀产物成分,研究了磷对低碳钢蚀孔扩展的影响机理.结果表明:在模拟蚀孔的闭塞区钢样阳极表面沉积物中有磷酸根离子存在,在蚀孔活化腐蚀过程中,钢中磷转化成磷酸根离子是在金属表面进行的,并形成磷酸盐沉积在金属表面,对蚀孔的扩展起抑制作用;磷含量不同的钢,表面沉积物中磷酸盐及磷酸根离子含量可相差很大,从而对蚀孔扩展的抑制作用也会有明显差异;同一钢样中,由于磷的偏析,在蚀孔扩展过程中高磷部位腐蚀速率较低,低磷部位腐蚀溶解速率较高,磷的偏析带导致了凸凹腐蚀沟槽的形成.The effect of phosphorus on the pitting propagation of low carbon steels was studied by specific occluded corrosion cell tests and by analyzing the corrosion products with an energy dispersive spectrometer.The results showed that there were phosphate ions in sediments on the surface of the steels in the occluded hole,and the phosphate ions were the production of phosphorus in the steels.During the activation of pits in corrosion,phosphorus converted into phosphate ions on the surface of the metal,then phosphates formed and deposited,and these phosphates inhibited the propagation of pits.Different contents of phosphorus in the steels could lead to a great difference of phosphate content on the surface of the steels,and the effects of pit propagation inhibition had a large difference too.In the same steel sample,because of phosphorus segregation,the corrosion rate was lower in the region of high phosphorus content than that of low phosphorus content.The formation of convexo-concave corrosion grooves was due to phosphorus segregation.

关 键 词：低碳钢 磷 点蚀 腐蚀速率 磷酸盐 

分 类 号：TG172.5[金属学及工艺—金属表面处理]