2507双相不锈钢在含铁氧化菌冷却水中的腐蚀行为

Corrosion Behavior of 2507 Duplex Stainless Steel in Cooling Water with Different IOB Contents

为研究2507双相不锈钢在含铁氧化菌IOB冷却水溶液中的腐蚀行为,采用失重法、扫描电镜和能谱及电化学测试等方法,分析了2507钢在含体积比为0.5%、1%及2%IOB冷却水模拟溶液中浸泡30d后的腐蚀行为.实验结果表明:冷却水溶液中含IOB大大加速了2507双相不锈钢的腐蚀,但腐蚀程度仍属轻度腐蚀,平均腐蚀速率随着IOB浓度增加先升后降,1%IOB下达到最大.随着IOB浓度增加结瘤形体增大,但均未出现点蚀坑,点蚀电位高达约1.25V.该钢抗含铁氧化菌冷却水的点腐蚀能力优良.

In order to study the corrosion behavior of 2507 duplex stainless steel in the cooling water simulation solutions with different iron oxidizing bacteria （IOB）contents for 30 days,it was investigated by using electrochemical measurement,weight loss,scanning electron microscopy （SEM）and energy dispersive spectrum （EDS）.The results showed：The corrosion rate of 2507 DSS in IOB solution was higher than in the sterile medium,but the corrosion degree was mild corrosion;The corrosion rate of 2507 DSS first rose and then fell when the IOB content increased,the maximum value of the corrosion rate was given at the 1% IOB content;The nodular corrosion increased along with the increase of IOB content,but 2507 DSS didn＇t happen pitting corrosion pit after corrosion for 30 days in the cooling water containing Cl- ,SO2 -4 and HCO-3 with IOB content,the pitting potential （E pit ）reached 1.25 V.