Abstract
The electrolyte was needed to control hydrogen content in high strength steel in a fracture experiment. Several buffer solutions such as boric acid-potassium chloride, acetic acid-sodium acetate and sulfuric acid-sodium sulfate were found useful to control hydrogen content. Also the addition of such as urea, thiourea or 3-(N-alkylamino) propionic acid in such electrolytes was found to change the hydrogen content in the range of 1/10 to 10 fold compared with that of no additive. By using such buffer solutions, the hydrogen content could be controlled over one week without regard to presence of cathodic polarization. Also the hydrogen content and its diffusion coefficient of SCM3 were measured as a function of tempering temperature. The increased in tempering temperature brought the decreased content and the increased diffusion coefficient. The activation energy in the diffusion process falled in the range of 6.4-7.4kcal/g.atom.
