普碳钢和不锈钢在极低质量浓度盐酸溶液中的腐蚀规律

Corrosion law of carbon steel and stainless steel in hydrochloric acid solution with extremely low mass concentration

为了探究钢种在酸性环境中腐蚀开始加剧的溶液质量浓度范围,研究了不锈钢和普碳钢在极低质量浓度HCl溶液中的腐蚀行为。参照不锈钢晶间腐蚀试验方法,进行了不同质量浓度HCl溶液和反应时间的腐蚀试验,通过测量钢样失重率、表面侵蚀面积和溶液pH值,研究了样品的腐蚀规律。试验结果表明：在质量浓度为300mg/L盐酸溶液中,普碳钢侵蚀程度较大,并且容易开始剧烈腐蚀,在0～4h侵蚀最剧烈,侵蚀进程较快;而不锈钢侵蚀程度较小,在0～28h内逐步被侵蚀,侵蚀进程较慢。当HCl质量浓度达到50～70mg/L时,普碳钢腐蚀开始加剧,不锈钢在HCl质量浓度达到90～100mg/L时腐蚀开始加剧。

To figure out the range of mass concentration that steel started to be corroded severely,corrosion behaviors of carbon steel and stainless steel in hydrochloric acid solution with extremely low concentration were investigated.According to the testing method of stainless steel intergranular corrosion,the corrosion experiments were conducted with different mass concentration of hydrochloric acid solution and reaction time.Weight loss rate,corrosion area of steel samples and pH change rate of the solution were measured to investigate the corrosion law.The results showed that carbon steel easily started to be corroded severely and the corrosion degree was higher in 300mg/L HCl solution.The most severe corrosion of carbon steel happened in 0-4hand the whole corrosion process was rapid.To stainless steel,the corrosion degree was lower and corrosion process went progressively in 0-28 h.The whole corrosion process was slower.When the mass concentration of HCl solution reached 50-70mg/L,carbon steel started to be corroded severely.And stainless steel started to be corroded severely when the mass concentration of HCl solution reached 90-100mg/L.