Deterioration in the Mechanical Strength of Commercial Carbon Steels Exposed in Various Environments

It is the purpose of this study to investigate losses in the tensile strength ratio, the true fracture strain ratio and the absorbed energy ratio to fracture of three different commercial carbon steels exposed in various environments of the air, the sea, the river and the soil. The results are given as parabolic functions of elapsed time in each environment. The concentration of the SO_2 content in the air was sensitive to the absorbed energy ratio of the SS-41 steel plate of one millimeter thickness in bright finished condition. Scale products yielded on three different steel specimens exposed in the air were examined by the X-ray diffraction method. Majority of them were determined to be the iron hydroxide FeO (OH) and no traces of iron oxides such as FeO, Fe_3O_4 and Fe_2O_3,iron sulfates such as FeSO_4 and iron chlorides such as FeCl_2 were confirmed.