The Inhibition Effect And Mechanism Of Hydrogen Anti-permeation Agent On Hydrogen Permeation And Hydrogen Induced Damage Of 27CrMo44S/1 Steel In H₂S-containing Acidic Solution

Because of energy shortage accompanied by economic development,an abundance of oil and gas resources have been exploiting.In the process of oil and gas mining and transportation,steel always be destroyed by Hydrogen Induced Damage(HID),a type of Hydrogen corrosion occurs in H2S-containing corrosive environment.This type of damage leads to decline in mechanical properties of equipment and sudden rupture on service,which causes a great loss in national economy.Therefore it is imperative for us to explore an effective,practical and environmental method for HID and Hydrogen embrittlement prevention.It has been discovered that X salt agent can effectively inhibit the “poison effect” of tensile stress and acidic environment on hydrogen permeation behavior and mechanical degradation of steel,and the hydrogen anti-permeation mechanism has been identified.The primary objective of this paper is to investigate the inhibition effect of X salt agent on hydrogen permeation,mechanical degradation,hydrogen blistering and HIC of steel in acidic H2S-containing solutions by hydrogen permeation tests,SSRT tests and hydrogen collection tests.Furthermore,by combination of chemical,electrochemical and morphological measurements,the hydrogen anti-permeation mechanism was identified.The results indicate that:Based on hydrogen permeation tests,after adding H2 S to acidic solution,the hydrogen permeation current density and inner diffusible hydrogen concentration improved by one order of magnitude and mechanical degradation happened severely.However,prior to H2 S,hydrogen anti-permeation agent was added in acidic solution.The process that corrosion product wraps X salt agent was prevented.The efficiency and long-term stability of hydrogen anti-permeation agent had been significantly enhanced.Appropriate concentration of hydrogen anti-permeation agent(1500ppm)effectively inhibited the hydrogen permeation behavior and mechanical degradation,decreased the sub-surface diffusible hydrogen concentration in H2S-containing acidic solutions.This mysterious result can be attributed to the superior nature of X species.X-precipitation on steel surface preferentially shielded the cathodic active site and increased the resistance of charge transfer,which leaded to the reduction of the propensity for accumulation and permeation of H.Whereas,at relative high concentration of hydrogen anti-permeation agent(?1500ppm),chloride ions in X salt agent inhibited the adsorption of X-precipitation on steel surface and shielded the cathodic active site.It increased the activity of hydrogen evolution reaction,brought about the high concentration of H,which is responsible for aggravation of hydrogen permeation behavior and HID susceptibility.