硫酸盐还原菌对海泥中Q235钢腐蚀界面的影响

从钢基体与腐蚀产物界面的角度,深入研究了海泥中硫酸盐还原菌对Q235钢的腐蚀行为的影响.结果表明,最初的腐蚀产物为铁的(水合)氧化物,在硫酸盐还原菌代谢活动的影响下,腐蚀产物逐渐向贫硫,以及富硫的铁硫化物转化.后者的晶体缺陷较多且结构疏松,不能阻挡Fe2 的扩散和侵蚀性离子的渗入,导致腐蚀加速.微生物的代谢产物以及腐蚀产物的转变为点蚀的形成和扩展提供了条件,其点蚀的位置一般发生在晶界和珠光体区,并沿晶界或珠光体扩展.

Study of effect of sulfate-reducing bacteria on corrosion interface between Q235 steel and sea mud

The corrosion behavior of Q235 steel influenced by sulfate-reducing bacteria(SRB)in sea mud was investigated from the point of view of corrosion interface for the first time by microbiological technique,metallographic microscope and electronic probe microanalyzer(EPMA).The results show that the original corrosion products,iron(hydr)oxides,gradually transform to low-sulfur and high-sulfur iron sulfides.For the crystal defect and loose structure of the latter,the diffusion of Fe~(2+)and penetration of aggressive ions can not be prevented,which accelerates the corrosion process.Furthermore microbial activity and transformation of corrosion products enable the formation and extension of pitting corrosion, which occurs and extends along the grain boundary and pearlite area.