Evaluation of Corrosion Rate and Diffusible Hydrogen Content of High Tensile Steel under Loading with Corrosion Environment

Abstract

Corrosion rate and diffusible hydrogen content of high tensile steel under constant load testing （CLT） in pH2 corrosive solution were investigated using electrochemical impedance spectroscopy （EIS） and thermal desorption spectroscopy （TDS）. R_p^－1 which is an index of corrosion rate increased as stress increased, which was correlated with the result of corrosion weight loss. This considered to be due to an increase in active nascent surfaces with increasing stress. Diffusible hydrogen content increased with stress, in particular by plastic deformation. The latter was more affected by the effect of corrosion rate and diffusible hydrogen content on stress. In other words, we have concluded that diffusible hydrogen content which related to hydrogen embrittlement was more affected by defects in steels by deformation than hydrogen entry from surface corrosion reaction in corrosion environment.