低合金鋼切欠き材における繰返し過大応力と水素侵入による疲労強度の低下

概要

論文の詳細を見る
Safety is one of the most important issues in hydrogen economy. Earthquake sometimes gives damages to steel structures and machineries. The components which had not been seriously damaged would still be used after the earthquake. The residual fatigue strength of those components, however, might have been decreased. The objective of this work is to clarify the effect of relatively small number of overloads and hydrogen on the residual fatigue strength of a notched component. As a result of the experiment, it was made clear that the formation of small crack and the tensile residual stress introduced by overloads caused substantial decrease of residual fatigue limit. The test results showed that the crack depth formed by overloads was about four times deeper in hydrogen charged material. The acceleration of low cycle fatigue crack growth by overloads played a major role. The reduction of ΔK_<th> also occurred. It gave secondary contribution for the reduction of residual fatigue limit.
社団法人日本機械学会の論文
2009-11-25