阴极充氢条件下氢在X80管线钢中的扩散行为研究

Study on Diffusion Behavior of Hydrogen in X80 Pipeline Steel Under the Condition of Cathode Hydrogen Charging

为了进一步预测管线在服役条件下的氢含量以及研究氢在材料中的扩散行为,采用电化学方法,对X80管线钢在稀H_2SO_4溶液中进行阴极充氢,并采用甘油置换法对试样吸收的氢含量进行测定。试验结果显示, X80管线钢在稀H_2SO_4溶液中电化学充氢时,延长充氢时间或增加充氢电流密度,可提高管线钢吸收氢的量,充氢48 h后吸收的可扩散氢含量基本达到稳定值;随氢浓度的增加,氢扩散系数由0.35×10^(-6) cm^2/s逐渐递增到0.47×10^(-6) cm^2/s。研究表明,在电化学充氢时间一定的情况下,充氢电流密度的增加加速了氢在金属中的扩散,使材料吸收氢含量得到提高。

In order to forecast hydrogen content of pipeline in service condition and study diffusion behavior of hydrogen in material, electrochemical method was used for X80 pipeline steel cathodic hydrogen charging in a dilute sulfuric acid solution, glycerol replacement method was used for testing hydrogen content absorbed by sample. The test results showed that the amount of hydrogen absorbed by X80 pipeline steel could be increased by extending the time of hydrogen charging or increasing the current density of hydrogen charging when it was electrochemically charged with hydrogen in dilute H2SO4 solution. The absorbed diffusible hydrogen content after hydrogen charging for 48 hours basically reached a stable value. With the increase of hydrogen concentration, hydrogen diffusion coefficient increased from 0.35×10^-6 cm^2/s to 0.47×10^-6 cm^2/s. The research indicated that the increase of hydrogen charging current density accelerated the diffusion of hydrogen in the metal, and improve absorbed hydrogen content at the same electrochemically charging hydrogen time.