Hydrogen permeation and hydrogen damage behavior of high strength casing steel in acidic environment

Abstract

To explore the effect of hydrogen permeation on pipes in an acidic environment, the tensile mechanical properties of three types of high strength steels were evaluated before and after hydrogen filling. The hydrogen damage behavior of three kinds of high-strength steels was studied by electrochemical hydrogen permeation test, MTS tensile test, and fracture morphology analysis. First, the basic physical and chemical properties of the materials were analyzed, and then the D-S double electrolytic cell technology was used for hydrogen permeation experiment. Finally, the influence of hydrogen loading on the tensile mechanical properties of the steel was determined by MTS tensile test and fracture morphology analysis. As the hydrogen filling current increases, the system temperature rises and the pH decreases, the hydrogen diffusion coefficient increases and the sensitivity of the steel to hydrogen embrittlement increases. The higher the steel strength, the higher the hydrogen diffusion coefficient, the higher the diffusible hydrogen concentration, the higher the hydrogen embrittlement sensitivity. The hydrogen damage evaluation method of high-strength steel used in this paper can provide a reference for the applicability evaluation of oil well pipe under acidic environment and provide theoretical guidance for the selection of oil well pipe in the field.