Corrosion of steel mains in media with different chemical compositions

The effect of different factors of corrosivity of grounds (hydrogen index, general acidity, concentration of Cl− and SO4−2 ions, degree of aeration) on the corrosion rate and hydrogenation of 17GS steel was investigated. The authors conclude that the corrosivity of grounds with low resistivity is determined by their pH values, general acidity and degree of aeration. For the case of acid and subacid grounds with low level of general acidity, their corrosion and hydrogenating impact can be modelled by a test in a deaerated solution with pH=5 and additives of Cl− ions. To estimate the maximum possible impact of the neutral and subacid grounds, the test should be carried out in a modified Parkins solution with pH=6. The corrosion and hydrogenating impact of the superacid grounds with medium and high general acidity can be modelled by the test in solutions with pH=4 and pH=3, respectively.