硫酸盐还原菌对热镀锌钢材氢渗透行为的影响

采用Devanathan-Stachurski 双面电解池检测氢渗透电流技术和扫描电镜分析, 研究了热镀锌钢材在灭菌海水、灭菌培养基和接种了硫酸盐还原菌(SRB)的培养基等3 种介质中的氢渗透行为。氢渗透电流检测结果表明, 培养基的部分组分对热镀锌钢材的氢渗透行为有促进作用, 试样在灭菌培养基中的氢渗透电流密度的平均值比在灭菌海水中提高了约6 倍。尽管活性SRB 代谢产生的S^2?和HS^?能够促进热镀锌钢材的氢渗透行为, 但是, 由SRB 及其代谢产物和它们所黏附的腐蚀产物所形成的致密微生物膜减少了氢的析出和试样对氢的吸收量, 导致热镀锌钢材氢渗透行为最终被抑制, 因此, 试样在接菌培养基中的氢渗透电流密度的平均值比其在灭菌培养基中降低77%。扫描电镜分析表明, 热镀锌钢材在灭菌海水中能够形成腐蚀产物膜, 而暴露于灭菌培养基中的试样表面未形成明显的腐蚀产物膜, 但在接菌培养基中试样表面能形成黏附了腐蚀产物的致密微生物膜的附着, 表明热镀锌钢材表面的微生物膜与其氢渗透行为之间存在明显的相关性。

Effect of SRB on hydrogen permeation of hot-dip galvanized steel

Hydrogen permeation testing with Devanathan-Stachurski cell and SEM analytical method were used to study the hydrogen permeation behavior of hot-dip galvanized steel in sterilized seawater, sterilized medium and medium inoculated with SRB. The results showed hydrogen permeation behavior of galvanized steel was promoted by some components of the medium. The average hydrogen permeation current density of the sample in sterilized medium was 6 times higher than which in sterilized seawater. The compact film formed by SRB, metabolites of SRB and corrosion products decreased the hydrogen adsorption of the sample although S^2? and HS^? produced by active SRB could promote the hydrogen peameation behavior, which resulted in the average hydrogen permeation current density of galvanized steel in medium inoculated with SRB 77% lower than which in sterilized medium. SEM results showed few products adhered on the sample immersed in sterilized medium, but a film of corrosion products was formed on the sample immersed in sterilized seawater, and a biofilm of SRB and its metabolites together with the film of corrosion products was formed on the the sample immersed in medium inoculated with SRB, indicating a obvious relation between the biofilm and hydrogen permeation of galvanized steel.