中高温域における疲労き裂進展ならびに下限界挙動

概要

論文の詳細を見る
Fatigue crack growth and closure were investigated in both SUS304 stainless steel and SM41A steel at elevated temperatures up to 500℃℃. A quantitative analysis was made of the roughness and oxide of the fracture surface at the near-threshold region. The effects of the roughness and the oxide on the fatigue threshold behavior were examined. The value of the threshold stress intensity factor range increased with increasing test temperature in both steels. An extra crack closure was not observed at elevated temperatures in SUS304 steel, although fracture surface roughness increased significantly with increasing test temperature. On the other hand, an elevation in the crack closure level was observed in SM41A steel due to the effect of the oxide products on the fracture surface at elevated temperatures. It was found that oxide-induced-crack-closure played an important role in effecting the crack closure at elevated temperatures, while roughness-induced-crack-closure had a less important effect on crack closure at near-threshold.
一般社団法人日本機械学会の論文
1986-01-25