利用挂片实验研究了8种可溶盐对涂层下金属腐蚀和涂层失效的影响规律.对A3钢基体，NH4Cl、NaSO4和Na2SO3的腐蚀促进作用接近，FeSO4的影响略大于前几种可溶盐，而NaCl的影响略小.NaNO3和NH4NO3只对涂层起泡有较大促进作用，对腐蚀的影响较小.NH4Cl对起泡和腐蚀均有较大的促进作用，而ZnCl2则有一定的抑制腐蚀作用.傅利叶变换红外光谱分析表明水分子和涂层分子的羰基C＝O形成氢键.扫描电镜和X-射线能谱分析表明可溶盐阴离子集中存在于表面的深坑中，对腐蚀的阳极反应(金属溶解)起加速作用.
Effect of 8 soluble salts on underfilm corrosion and failure of the coatings of A3 steel was studied by means of exposure.The results show that the acceleration of NaCl,NH4Cl,Na2SO4,Na2SO3 and FeSO4 to corrosion of A3 steel substrate are all considerable,but that of NaCl is a little less than those of NH4Cl,Na2SO4,Na2SO3;and that of FeSO4 is slightly greater than those of the former.NaNO3 and NH4NO3 acceleates greatly blistering of the coatings and affects relatively less the corosion of the substrate.ZnCl2,however,has no harmful effect either on corrosion of the substrate or on degradation of the coatings,and even has some inhibiting effect on corosion of the substrate.Polyurethane coating provides better protection than alkyd coating.FTIR analysis shows that H-bond is formed between the water molecule and the C=O group of the coatings.And therefore the water can permeate through the coatings much faster than O2.SEM and EDAX analysis showed that the anions of the soluble salts exsit in the pits of the surface and accelerate the anodic reaction.
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