一种车用低合金铸钢氢扩散系数的测定方法

摘要

采用双电解池电化学氢渗透法测试氢在一种低合金铸钢中的扩散系数,并利用基于半无限扩散模型的氢渗透修正公式,分析试样厚度、充氢电流密度和测试温度等因素对氢扩散系数测定值的影响规律.结果表明:试样厚度对氢扩散系数测量值没有明显影响,不过从材料均匀性方面考虑,选取较厚的试样应获得更准确的测试值;充氢电流密度越大,表观氢扩散系数与理论值越接近;氢扩散系数随测试温度升高而增大,其关系式为D=0.052 8 exp(-22.47/RT).%The method of electrochemical hydrogen permeation in a double electrolytic cell was applied to measure the diffusion coefficient of hydrogen in a low alloy cast steel.The modified hydrogen permeation formula based on semi-infinite diffusion model was applied to evaluate the effects of the thickness of testing specimen,the current of charging hydrogen and experimental temperature on the measured value.The results indicate that the thickness of experimental sample did not exert influence on the measured value of diffusion coefficient of hydrogen.However,from the viewpoint of homogeneity of the material,more accurate measured value would be obtained by measuring a thicker sample,the observed value was closer to the theoretical value with increasing the current density of charging hydrogen.Rising experimental temperature could increase the diffusion coefficient of hydrogen,D=0.052 8 exp (-22.47/RT).