低炭素鋼平滑材の疲労き裂進展挙動に及ぼすひずみ時効の影響

概要

論文の詳細を見る
Precracked specimens of a low temperature quenched rimmed steel were fatigued in rotating bending. Stage-II precracks were introduced by cyclic stressing at a overstress level to the length of 500 μm. The specimens were aged under cyclic stressing at understates levels for 10^6 to 10^7cycles (dynamic strain ageing) or statically aged at 100℃ for 40 minutes or at room temperature for 24 to 48 hours corresponding to 5 x 10^6 to 10^7 cycles and for 6 weeks (static strain ageing), and then fatigued at the same overstress level as before. The main results obtained are summarized as follows : (1) Dynamic strain ageing contributes to the decrease in propagation rate but hardly to the increase in critical propagation stress of the precracks. (2) Static strain ageing at room temperature for 24 to 48 hours influences both the propagation rate and the critical propagation stress to the same extent as dynamic strain ageing. (3) Static strain ageing at room temperature for 6 weeks and at 100℃ for 40 minutes makes a greater contribution to the decrease in propagation rate and the increase in critical propagation stress than the above other strain ageing treatments.
社団法人日本材料学会の論文
1978-09-15