The Effect Of The Degradation Products Of Sodium Alginate On The Q235 Steel Corrosion Behavior In 35‰NaCl Solution

Corrosion is one of the most destructive factors in modern industry and daily life, corrosion loss is about 500 billion RMB in our country, and corrosion loss accounted for about 6 percent in the total GDP(General Domestic Products). So it is very important significance to study the corrosion process of mild carbon steel. From point view of environmental protection and sustain development, a lot of research and development of environmental friendly corrosion inhibitor was studied and natural material is one of them. So it is very significant to study the corrosion mechanism of natural materials to mild carbon steel in sea water, and it can provide guide significance to develop corrosion inhibitor.Oxidative degradation method was selected to degrade sodium alginate for getting lower molecular weight sodium alginate, and then weight loss, combined with electrochemical polarization and elliptical polarization method in situ, was performed in 35‰NaCl corrosive medium to examine the corrosion character of degradation products to mild carbon steel. The compounds, which consist of degradation products of sodium and Na2CrO4,Na2MoO4,Na3PO4 and ZnSO4 respectively, were studied with electrochemical polarization and elliptical polarization method in situ in 35‰NaCl corrosive medium at the same time. Semi-empirical quantum mechanical method was used to optimize the molecular structure of sodium alginate oligosaccharides in ground-state and the stable space structure was obtained. Adsorption state of sodium alginate oligosaccharides, on the mild carbon steel, was conducted combined with optimized molecular structure.According to the experiment data we can draw the conclusion: (1) we use Semi-empirical quantum mechanical method to optimize the molecular structure of...