摘要
在室内模拟条件下研究了在海泥中硫酸盐还原菌 (SRB)对A3钢电偶效应的影响。实验在两个大型塑料槽中进行。A3钢样尺寸为 2 0cm× 1 0cm× 0 .3cm ,海泥中SRB的含量用MPN三管计数法进行测定 ;电导率、pH、氧化还原电位、泥温和盐度等参数用SY - 5型电导 -pH/mV -温度计进行测量 ;用失重法测量腐蚀速度 ;用零电阻表测量电偶电流。试验共进行 2 61d。SRB含量随时间的变化基本保持恒定。在电偶条件下A3钢在灭菌泥和有菌泥中的腐蚀速度分别为0 0 0 77mm/a和 0 0 4 9mm/a,在非电偶条件下A3钢在灭菌泥和有菌泥中的腐蚀速度分别为 0 0 0 89mm/a和 0 0 4 4mm/a。A3钢在有菌泥和无菌泥中的样板之间的电偶电流随时间的变化幅度在2 5μA左右 ,且有方向逆转现象。试验结果表明 ,在有菌泥中A3钢的腐蚀速度是无菌泥中的 5 5倍 ,说明SRB在海泥腐蚀中有重要作用。埋在相邻的有菌海泥和无菌海泥的试样之间都发生了电偶腐蚀。处在有菌海泥中的钢样为电偶对的阳极 ,处在无菌海泥中的钢样为电偶对的阴极。在实验期间内电偶效应对试样的加速作用为 1 1 .4%。
The effect of sulfate reducing bacteria(SRB) on corrosion of steel is a main factor in sea mud. In this paper, the effect of SRB on galvanic action of A 3 steel in sea mud has been studied in laboratory under simulated conditions. The test was performed in two large plastic troughs for 261 days. The size of A 3 steel sample was 20cm×10cm×0. 3cm. The content of SRB in sea mud was measured by MPN tri-tube method and kept basically no change with time during the test is shown in Fig. 2. The conductance, pH, potential of oxidation-reduction, temperature, salt content in sea mud was measured by an SY-5 type conductance-pH/mV-thermometer. The corrosion rate was measured by weight loss method and the result obtained is shown in table 1. The galvanic current was measured by zero-resistance current meter, and the change of galvanic couple current of A 3 steel samples between bacterial and bacteria-free sea mud with time is shown in Fig. 3. The results show that(1) the corrosion rate of A 3 steel in bacterial sea mud is 5. 5 times that in bacteria-free sea mud;(2)galvanic corrosion occurs between steel samples (with the same properties)buried in bacterial and bacteria-free sea mud. The steel samples in the bacterial sea mud were the anode of galvanic couple and the steel samples in the bacteria-free sea mud were the cathode of galvanic couple. Accelerate rate of galvanic action on corrosion of anodic samples is around 11. 4%.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2000年第4期448-452,共5页
Oceanologia Et Limnologia Sinica
基金
国家自然科学基金资助项目!4 92 762 72号
"九五"中国科学院资源与生态环境研究重大资助项目!KZ951 -A1-4 0 5-0 4号
关键词
海泥
硫酸盐还原菌
钢铁
电偶效应
腐蚀
Sea mud Sulfate reducing bacteria(SRB) Steel Galvanic action