Effects of Chromium and Molybdenum on Hydrogen Absorption Behavior in Iron

摘要

Effects of chromium and molybdenum on hydrogen absorption behavior in iron have been investigated by determining the equilibrium concentration of hydrogen (C_H) and calculating the heat of solution of hydrogen (AH) in pure Fe, Fe-2.37Cr, and Fe-4.23Mo. Specimens were chemically polished prior to cathodic hydrogen charging. They were charged with hydrogen in a solution of 0.1 N NaOH and 5 gl~(-1) NH_4SCN at 30 °C with different charging times to determine C_H. To calculate △H, they were charged with hydrogen at various temperatures (30,40, and 50 °C). As results, C_H in pure Fe was the highest, whereas that in Fe-4.23Mo was the lowest. It was also found that AH values of Fe-4.23Mo and Fe-2.37Cr were positive with that the former was being the highest. Moreover, the pure Fe specimen applied strain of 0.3 had a higher negative value of AH than pure Fe. These findings indicate that a solid solution of Mo in Fe reduces C_H compared with that of Cr.