説明:
(abstract)Achieving superior fracture resistance under cyclic loading–specifically, a high-fatigue limit–is crucial for ensuring structural safety and supporting a sustainable society. This study demonstrates a breakthrough in overcoming the conventional fatigue limit ceiling in high-strength as-quenched martensitic steel by enhancing resistance to crack initiation. In the as-heat-treated state, high-angle boundaries with large elastic misfits and plastic incompatibility served as precursory sites for intrusions/extrusions (these are defined as “crack embryos”), eventually leading to fatigue crack initiation. Remarkably, after the pre-fatigue training, surface crack initiation is entirely suppressed, doubling the fatigue limit with minimal change in tensile strength. A novel concept of “crack embryo engineering” is introduced, which targets the prevention of crack embryo formation by extracting intrinsic microstructural self-optimization against fatigue deformation: macroscopic hardness homogenization and selective nano-hardening of the precursory sites. This self-optimization strategy offers a versatile approach to improving fatigue limit in general steels, providing an effective alternative to tempering heat treatment that inevitably sacrifices tensile strength.
権利情報:
刊行年月日: 2025-06-29
出版者: Wiley
掲載誌:
研究助成金:
原稿種別: 出版者版 (Version of record)
MDR DOI:
公開URL: https://doi.org/10.1002/advs.202504165
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その他の識別子:
連絡先:
更新時刻: 2025-11-11 16:30:06 +0900
MDRでの公開時刻: 2025-11-11 16:24:13 +0900
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Advanced Science - 2025 - Okada - Fatigue Limit Doubling in High‐Strength Martensitic Steel through Crack Embryo.pdf
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サイズ | 3.23MB | 詳細 |