Verification of the prediction methods of strain range in notched specimens made of Mod.9Cr-1Mo

改良9Cr-1Mo鋼切り欠き試験片によるひずみ範囲予測法の検証

安藤 勝訓 ; 廣瀬 悠一*; 伊達 新吾*; 渡邊 壮太*; 江沼 康弘*; 川崎 信史 

Ando, Masanori; Hirose, Yuichi*; Date, Shingo*; Watanabe, Sota*; Enuma, Yasuhiro*; Kawasaki, Nobuchika

高温における構造物のひずみ範囲予測法の妥当性を検証するため、切り欠き試験片による低サイクル疲労試験を実施した。試験はJSFRの冷却系機器・配管材として採用される予定の改良9Cr-1Mo鋼により実施し、疲労試験中のき裂の発生及び進展状況を観察した。この試験結果と有限要素法解析に基づくひずみ範囲予測法であるSRL法,弾性追従による予測法,ノイバー則による予測法及び既往の高温構造設計方針における評価法を比較し、その適用性等について述べる。

To verify the strain prediction method of discontinues structures at evaluated temperature, low cycle fatigue tests were carried out with notched specimens made of Mod.9Cr-1Mo. Deformation control fatigue tests and thermal fatigue tests were performed by ordinary uni-axial push-pull test machine and equipments generating the thermal gradient in the notched plate by induction heating. Crack initiation and propagation process during the fatigue test were observed by the digital micro-scope and replica method. Then the ranges of several strain predictions and estimations were compared with the test results. Stress Reduction Locus (SRL) method, simple elastic follow-up method, Neuber's rule method and the methods supplied by elevated temperature design standards were applied. Through these results, the applicability and conservativeness of these strain prediction and estimation methods is discussed.