The Influence of Secondary Forming on Delayed Fracture Behavior at Sheared Edges
せん断端面の遅れ破壊特性に与える端面二次成形の影響について
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- Available on the other site
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- Publication code
- 20264181
- Paper/Info type
- JSAE Transaction
Vol.57 No.2
- Pages
- 284-289(Total 6 p)
- Date of publication
- Mar 2026
- Publisher
- JSAE
- Language
- Japanese
Detailed Information
| Category(J) | 論文 Translation |
|---|---|
| Category(E) | Paper |
| Author(J) | 1) 松木 優一, 2) 戸畑 潤也, 3) 新宮 豊久, 4) 木村 英之, 5) 塩崎 毅 |
| Author(E) | 1) Yuichi Matsuki, 2) Junya Tobata, 3) Toyohisa Shinmiya, 4) Hideyuki Kimura, 5) Takeshi Shiozaki |
| Affiliation(J) | 1) JFEスチール(株), 2) JFEスチール(株), 3) JFEスチール(株), 4) JFEスチール(株), 5) JFEスチール(株) |
| Abstract(J) | 自動車車体の軽量化と衝突特性の両立のため超高強度鋼板の適用が拡大しているが，せん断端面での遅れ破壊が課題である．本研究では超高強度鋼板に対してせん断加工を行い，せん断端面に引張と圧縮の二次成形を付与し，その後応力負荷した状態で遅れ破壊試験を実施することで，遅れ破壊特性への影響を調査し考察を行った． Translation |
| Abstract(E) | The evaluation of delayed fracture resistance is one of the major issues for the application of high strength steel sheets to automotive parts. We are proposing a method for evaluating delayed fracture resistance using the four-point bending test specimen. The purpose of this study is to clarify the effect of the strain by secondary forming on the sheared edge delayed fracture resistance of the ultra-high strength steel sheets. The material used in this study is a martensitic steel sheet with a tensile strength of 1470MPa. The specimens were shear‑blanked and subsequently subjected to secondary forming, either tensile deformation by stretching or compressive deformation by deep drawing. The delayed fracture resistance was investigated by conducting immersion tests using four-point bending test specimens in a solution of 0.1%NH4SCN+McIlvaine buffer for 96 hours. It was suggested that the small amount of secondary forming could improve the delayed fracture resistance because of the stress alleviation of residual stress by shearing. However, the delayed fracture resistance was deteriorated when the forming strain is too large because of the accumulated damage and heterogeneity on the edge surface. The variation of delayed fracture resistance by secondary forming amount was discussed by the combination of stress alleviation and damages on the sheared edge. |
