抄録
Commercial pure iron was decarburized in wet-hydrogen atmosphere after grain size adjustment, charged with nitrogen or carbon and tested by the tensile testing machine. The nitrogen or carbon content was determined by means of internal friction measurement. The yield stress, aging index, yield point elongation and other tensile properties were measured as a function of nitrogen or carbon content. Also at definite strains, the relaxed stress was measured which is the strain rate dependent part of flow stress. This part was analysed by Johnston’s theory and the stress exponent n, and the stress required to move a dislocation with unit velocity τ0 were calculated as a function of nitrogen or carbon content. The relation between this theory and Conrad’s was also discussed.
