材料期刊网

目的：研究室内腐蚀膏试验对430不锈钢的加速性，以及腐蚀膏试验与大气暴露腐蚀试验的相关性。方法采用室内腐蚀膏腐蚀试验对材料进行腐蚀，研究其腐蚀过程的电化学特性和机理，腐蚀产物形貌、组成和结构，以及腐蚀过程的动力学规律，并与材料大气环境暴露试验的结果对比，探讨腐蚀膏试验与大气暴露试验的相关性。最后计算出室内腐蚀膏试验对430不锈钢的加速性。结果430不锈钢在腐蚀膏腐蚀试验中，腐蚀失重与时间方程为 P=0.3998t1.0391，呈幂指数关系，在腐蚀初期腐蚀速度最大。腐蚀机理主要是点蚀。由于腐蚀膏中的Cl-对钝化膜的穿透作用，使得钝化膜在一定点能够维持高的电流密度，并使阳离子杂乱移动而活跃起来，当膜-溶液界面电场达到临界值，点蚀发生。腐蚀表面存在点蚀坑，且随着腐蚀时间的增加，点蚀区域增加，相邻点蚀相互连接，形成腐蚀面。腐蚀面可见红色锈斑，对腐蚀产物进行XPS分析，其主要成分为FeOOH和Fe3O4。430不锈钢在大气环境的腐蚀过程中，其腐蚀机理也是点蚀，腐蚀失重与时间也呈幂指数关系，腐蚀产物和形貌结构与室内腐蚀膏试验相同。结论腐蚀膏试验对430不锈钢腐蚀具有加速性，且与其大气暴露试验具有相关性，可以作为模拟430不锈钢大气腐蚀的一种加速试验。

ABSTRACT:Objective To investigate the acceleration of 430 stainless steel in Corrodkote corrosion test and the correlation between atmospheric exposure corrosion test and Corrodkote corrosion test.MethodsCORR test was carried out on the material corrosion. The electro-chemical properties and mechanism of the corrosion process, the morphology of corrosion products, composition and structure, and corrosion kinetics of the process were studied to draw the correlation between the two tests. Fi-nally, the acceleration of 430 stainless steel in indoor CORR test was calculated.Results In CORR test, the equation of corro-sion weight loss of 430 stainless steel vs. time wasP=0.3998t1.0391, and the corrosion rate was the largest at the beginning of the corrosion. Corrosion mechanism was mainly pitting corrosion. Passivation film could maintain high current density at a fixed point due to the penetration of passivation membrane by Cl ion, driving the cation to move disorderly and become active. When the film-solution interface electric field reached the critical value, pitting corrosion occurred. With the increase of corrosion time, pitting area increased, and adjacent pittings connected each other, forming corrosion surface. Red rust was observed on the corrosion sur-face. XPS analysis was carried out on the corrosion products, revealing the main components as FeOOH and Fe3O4. In the corrosion process of 430 stainless steel in atmospheric environment, the mechanism of corrosion was pitting, the corrosion weight loss and time also assumed the power relations, the corrosion products and morphology structure were the same as those of the CORR test. ConclusionThe CORR test had corrosion acceleration for 430 stainless steel. There was a good correlativity between accelerated test and outdoor exposure test. The CORR test could be used to simulating the atmospheric corrosion of 430 stainless steel.