研究了一种低碳钢在于湿交替腐蚀加速实验条件下的锈蚀速度变化.结果表明:在初期,锈蚀速度随干湿交替次数的增加而增大,随后转为随干湿交替次数的增加而降低;低碳钢锈蚀速度的转变与铁锈组成的变化有关,γ-FeOOH和Fe3O4的形成是腐蚀速度出现转化的因素之一.带锈低碳钢的电化学极化行为表明,干湿交替初期的腐蚀产物对阴极和阳极过程都有促进作用,在后期表现为对阳极过程抑制,而对阴极过程促进.同时,提出了一种描述低碳钢大气腐蚀行为的流程图.
Corrosion rate of mild steel under wet/dry alternate conditions with 0.3 % NaCl solution was studied. The corrosion rate increased with increasing wet/dry alternate cycles in the initial stage, while it decreased in the later stage. The transformation of corrosion rate of mild steel related to the evolvution of the rust composition, which may be characterized by the occurrence of γ- FeOOH and Fe3O4 in the rust layer. Polarization curves of the rusted mild steel in 0.3 % NaCl solution showed that the corrosion products formed in the initial stage accelerated both anodic and cathodic process, while in the later stage it suppressed the anodic process and accelerated the cathodic process. A flow chart was proposed to describe the atmospheric corrosion behavior of mild steel.