実働荷重かにおけるき裂進展とふん囲気の影響

概要

論文の詳細を見る
The effects of stress history and corrosive environment on fatigue crack propagation of mild steel are discussed under the constant and the variable stress amplitude, and the following facts are made clear: The crack initiation of corrosion fatigue is very early but the crack rate in saline and in water becomes smaller than that in air from a certain value of crack depth. This may be due to the wedge action of metal oxide in cracks. In hydrochloric acid the decrease of the crack rate is not observed because of the dissolution of metal oxide. Under high-low two-step stress history, both in air and in saline the crack propagation is delayed for a considerable period of time after the stress change and the subsequent crack rate is found to be nearly equal to the expection for the lower stress. On the other hand, under low-high two-step stress history, the rate in air is that which would be expected after the transition to the higher stress, while the rate in saline is a little greater than the expection for a while after the stress change, then gradually decreases to the expection. In saline Σ(n/N) is smaller than unity under low-high stresses, while Σ(n/N) is greater than unity under high-low stresses. Consequently, Σ(n/N)≈1 is concluded in saline under two-stress repeated block history because of the mutual offset of these effects. Since the life of smooth specimens in corrosive environment is wholly occupied by crack propagation, the same argument for the notched specimens mentioned above will be applicable to the corrosion fatigue of smooth specimens under variable stress history.
社団法人日本材料学会の論文
1968-02-15

実働荷重かにおけるき裂進展とふん囲気の影響

スポンサーリンク

概要

著者

関連論文

スポンサーリンク