超高强钢丝锌铝合金镀层腐蚀的元胞自动机模拟方法

Corrosion Simulation Method of Ultra-high Strength Steel Wire Zinc-aluminum Alloy Coatings Based on Cellular Automata

根据锌铝合金镀层的电化学腐蚀原理,结合锌铝合金镀层微观组织试验、镀层均匀性试验、中性盐雾腐蚀试验数据,建立适用于锌铝合金镀层的二维腐蚀元胞自动机模型,模拟锌铝合金镀层的腐蚀演化过程,分析镀层金属氧化反应、水化反应、水化物溶解反应和镀层不均匀性对腐蚀过程的影响规律.研究结果表明,二维腐蚀元胞自动机模型能够准确模拟锌铝合金镀层的腐蚀演化过程;在镀层腐蚀过程中,金属的氧化反应起主导作用,金属的水化反应和金属水化物的溶解反应是次要因素;同一时刻,氧化概率大小与单位面积金属腐蚀量呈非线性正比关系,溶解概率大小与单位面积金属腐蚀量呈非线性正比关系,水化概率大小与单位面积金属腐蚀量呈反比关系;镀层金属含量的不均匀分布对镀层腐蚀演化过程影响较小,镀层厚度的不均匀性会导致局部区域铁基体过早发生腐蚀,引起蚀坑的出现.

According to the electrochemical corrosion principle of zinc-aluminum alloy coating,combined with the data of coating microstructure test,uniformity test,and neutral salt spray corrosion test,a two-dimensional corrosion cellular automaton model of zinc-aluminum alloy coating was developed,and the corrosion process of zincaluminum alloy coating was simulated.Then,the influence of the coating metal oxidation,the coating metal hydration,the hydrate dissolution,and the coating non-uniformity on the corrosion process were analyzed.The research results indicate that the two-dimensional corrosion cellular automata model can accurately simulate the corrosion process of zinc-aluminum alloy coatings.During the coating corrosion,metal oxidation plays a leading role,and metal hydration and metal hydrate dissolution are secondary factors.At the same time,the oxidation probability is nonlinearly proportional to the amount of metal corrosion per unit area,the dissolution probability is nonlinearly proportional to the amount of metal corrosion per unit area,and the hydration probability is inversely proportional to the amount of metal corrosion per unit area.The uneven distribution of metal content in the coating has little effect on the coating corrosion process,but the coating uneven thickness leads to premature corrosion of the iron matrix in local areas,resulting in the appearance of pitting pits.