柠檬酸环境友好钝化液配方研究

针对传统的不锈钢钝化液使用浓硝酸、浓硫酸、铬酸等强氧化剂存在较高的安全隐患,操作条件苛刻的问题,采用挂片在滚筒中旋转浸泡的方式进行钝化,研究不锈钢柠檬酸双氧水钝化工艺,探讨最佳工艺条件,并利用塔菲尔曲线测得其自腐蚀电流密度以表征其耐腐蚀性能.研究表明:钝化效果的影响因素显著性顺序为柠檬酸质量分数>双氧水质量分数>钝化温度>钝化时间;柠檬酸环境友好钝化液的最佳配方为:柠檬酸质量分数10%,双氧水质量分数15%,稳定剂F质量分数15%,缓蚀剂E质量分数1%,温度40,℃,钝化时间60,min.柠檬酸双氧水钝化后测得不锈钢自腐蚀电流密度为5.210×10-6,μA/cm2,小于传统钝化后测得的不锈钢自腐蚀电流密度(6.098×10-6,μA/cm2).新型的柠檬酸配方钝化效果比传统配方的钝化效果好,对环境的污染负荷小,为化工集装罐实际钝化应用提供了基础数据.

Research of Environmentally Friendly Passivation Using Citric Acid Formulations

Against the higher hidden danger and the harsher working conditions of the traditional stainless steel passivation formulations which uses nitric acid,sulfuric acid,chromic acid and other strong oxidants,method of coupon rotating immersed in the drum was used.The stainless steel passivation process of using citric acid and hydrogen peroxide was studied,inquire into the optimum process condition,and Tafel plot was used to measure the corrosion current density so as to express its corrosion resistance.The study indicated that the order of the effects on the passivation result was the content of citric acid,the content of hydrogen peroxide,passivation temperature,and the passivation time.The optimum parameters of passivation in citric acid solution are 10% citric acid,15% hydrogen peroxide,15% stabilizer F,1% corrosion inhibitor E,40,℃,and 60,min.The potentiodynamic polarization test revealed lower corrosion current density of the new formula of citric acid(5.210×10-6,μA/cm2)than that of the traditional one(6.098×10-6,μA/cm2),indicating better corrosion resistance of the new formula using citric acid than the traditional one,and as citric acid is an organic acid,the load of environmental pollution was light.Basic data were provided for practical passive application of the chemical tank containers.