研究电化学充氢过程中X70钢氢吸收的新方法

提出了一种测定管道钢阴极充氢或阴极保护过程中氢吸收的新方法.将阴极预充氢试样在稀NaOH溶液中恒电位阳极极化,测量了试样中吸收氢的脱附(氧化)电流随时间的变化曲线.利用该曲线分析吸收氢的量,并建立其与预充氢电流密度、充氢时间及充氢溶液pH间的关系,探索用于评价X70管道钢对阴极充氢敏感性的指标.结果表明,在双对数坐标中试样中的氢浓度分别是预充氢电流密度和时间的单增函数.降低充氢溶液pH可大大提高X70钢的氢吸收量.

A new method of measuring hydrogen absorption of electrochemical precharged X70 steel

Based on electrochemical techniques, a convenient method was proposed to measure hydrogen absorption of pipeline steels during electrochemical hydrogen charging. The hydrogen desorption current of the electrochemical precharged steel membrane as a function of the time was measured under potentiostatically anodic polarization. The absorbed hydrogen content was obtained by the definite integral of desorption current with respect to time. The absorbed hydrogen content was measured as functions of the precharging current, the pH of the precharging solution and the precharging time. The results show that the absorbed hydrogen content is monotonically increasing functions of precharging current and precharging time in the log-log scale. The effect of pH of precharging solutions on absorbed hydrogen depends on the range of alkalinity or acidity.