Improvement of Fatigue Crack Propagation Property in Low Carbon Steel by Microstructural Control and an Investigation of its Practical Benefit
-
- Hyodo Yoshihiro
- Steel Products Research Department, Steel Research Laboratory, JFE Steel Corporation
-
- Yuga Masao
- Steel Products Research Department, Steel Research Laboratory, JFE Steel Corporation
-
- Kurihara Yasuyuki
- Civil & Infrastructure Engineering Research Department, Steel Research Laboratory, JFE Steel Corporation
-
- Doan Thi-Huyen
- Civil & Infrastructure Engineering Research Department, Steel Research Laboratory, JFE Steel Corporation
-
- Sakimoto Takahiro
- Joining & Strength Research Department, Steel Research Laboratory, JFE Steel Corporation
-
- Murakami Yoshiaki
- Technology Planning Department, JFE Steel Corporation
-
- Gotoh Koji
- Department of Marine Systems Engineering, Faculty of Engineering, Kyushu University
-
- Tagawa Tetsuya
- Steel Research Laboratory, JFE Steel Corporation
抄録
<p>The fatigue crack propagation properties of newly-developed SM490 grade steels were investigated in comparison with a conventional steel of the same grade. The fatigue crack propagation rate of the developed steel in Region II of the da/dN-ΔK relationship was suppressed to about 1/2 that of the conventional steel, and its ΔKth value was more than twice as large as in the conventional steel. However, fatigue crack resistance for long crack propagation does not necessarily improve the fatigue life in a condition of increasing ΔK from a small defect, which is usually detected in practical fatigue damage in actual structures in service. The developed steels were subjected to surface crack propagation tests using specimens with artificial small defects to examine their potential under more practical conditions. The fatigue life of the developed steel was about three times longer than that of the conventional steel. A detailed analysis of the surface crack propagation revealed crack propagation below ΔKth only in the developed steels, which suggested the so-called “short crack regime” in a fatigue crack. The crack propagation from a surface defect that deviated from long crack behavior was convincingly explained by the corrected threshold using the R-curve model of a short crack proposed in the previous literature. Based on the experimental fatigue life improvement and its analytical estimation of the propagation resistance in the short crack regime, the effect of the ΔKth value for a long crack in the initial propagation stage just after fatigue crack initiation was discussed.</p>
収録刊行物
-
- ISIJ International
-
ISIJ International 63 (10), 1738-1746, 2023-10-15
一般社団法人 日本鉄鋼協会
- Tweet
キーワード
詳細情報 詳細情報について
-
- CRID
- 1390860764355854208
-
- ISSN
- 13475460
- 09151559
-
- 本文言語コード
- en
-
- データソース種別
-
- JaLC
- Crossref
-
- 抄録ライセンスフラグ
- 使用不可