高酸高氯原油水中曼尼希碱对316L不锈钢的缓蚀作用

Inhibition Action of Mannich Base for 316L Stainless Steel in Chlorine-Containing Highly Acidic Crude Oil Aqueous Solution

原油的氯腐蚀严重影响石油化工装置的安全运转,控制氯腐蚀有多种途径,其中添加缓蚀剂是最简单、快捷的方法。通过室内静态挂片失重法、CMB-4510A缓蚀剂快速评定仪和SEM,研究了316L不锈钢在原油模拟水中的氯腐蚀特性及曼尼希碱与硅酸钠复配对其缓蚀效果的影响。结果表明:腐蚀溶液的pH值、温度和Cl-浓度对316L不锈钢的腐蚀速率都有明显的影响;曼尼希碱可以在金属表面形成一层保护膜,有效阻止去极化物质向金属表面的迁移,当曼尼希碱质量分数为1%时缓蚀效果最好,缓蚀率达83.78%;曼尼希碱与硅酸钠之间有很好的协同效应,有效地降低了金属的腐蚀速率。

The inhibition action of the mixture of Man-nich base and sodium silicate for 316L stainless steel in simulated crude oil aqueous solution was investigated by making use of a static coupon weight loss method as well as a rapid assessment in-strument for corrosion inhibitors and a scanning electron micro-scope.Results show that pH value,temperature and Cl-concen-tration of the corrosive solution have significant effects on the cor-rosion rate of the steel.Mannich base was able to form protective films on metal surface and hence prevent depolarized substance from transferring towards the metal surface.An inhibition effi-ciency of 83.78% was obtained at a Mannich base dosage of 1%.Besides,a synergistic inhibition effect existed for Mannich base and sodium silicate,greatly reducing the corrosion rate of stainless steel.