CO2环境对X80管线钢氢渗透行为的影响

摘要

由于以往的研究忽视了CO2对氢渗透的促进作用,所以利用高压反应釜氢渗透测量系统研究了中性和酸性环境中CO2对X80管线钢氢渗透行为影响.研究发现CO2对氢渗透具有促进作用,在中性环境中CO2的氢促进作用为 H2S的1/20,腐蚀速率比较低,FeCO3腐蚀产物呈颗粒状,对氢渗透电流无明显影响.酸性环境中CO2氢促进作用增大为 H2S的1/10,腐蚀速率较中性CO2条件下提高了3倍,FeCO3腐蚀产物膜将基体表面完全覆盖.反应初期颗粒状FeCO3腐蚀产物增大了CO2的附着面积而促进氢渗透,随着腐蚀产物膜加厚,对氢渗透具有抑制作用,造成氢渗透曲线值的降低.%The role of CO2 in promoting hydrogen permeation has not yet thoroughly investigated in previous studies.In this paper,a hydrogen permeation measurement system within a high pressure reaction kettle was used to study the effect of CO2 on hydrogen permeation behavior of X80 pipeline in neutral and acidic environments.It is found that CO2 has a promoting effect on the hydrogen permeation.In the neutral environment,the hydrogen permeation acceleration effect of CO2 is about 1/20 of H2S,the corrosion rate is relatively lower,the corrosion product of FeCO3appears as the coarse granular bainite,and has no obvious effect on the hydrogen permeation current.In the acidic environment,the hydrogen permeation acceleration effect of CO2 is about 1/10 of H2S,and the corrosion rate was 3 times higher than that of neutral CO2.The surface of metal substrate was completely covered by FeCO 3corrosion product.At the beginning of the reaction,the corrosion products increased the bond area of CO2 and promoted the hydrogen permeation,and the hydrogen permeation curve was reduced with the inhibition of hydrogen permeation by the thickening of the corrosion product deposit.