旧オーステナイト粒径の異なる18%Niマルエージング鋼の破壊靱性およびストレッチ・ゾーン

書誌事項

タイトル別名
  • Plane Strain Fracture Toughness and Stretched Zone of an 18%Ni Maraging Steel with Various Prior-Austenite Grain Sizes
  • キュウ オーステナイト リュウケイ ノ コトナル 18パーセント Ni マルエ

この論文をさがす

抄録

The effect of prior austenite (γ) grain or martensite (α') packet size on the plane strain fracture toughness (KIC) and the correlation between the stretched zone width and KIC of an 18% Ni maraging steel were studied by means of fracture toughness testing and fractography.<BR>KIC was not affected by γ grain size in the fine (6.7-15.7μ) or coarse (118μ) region, while it increased in the intermediate grain size range from 28.3 to 90.4μ. In the latter condition, the plastic zone spread over about one to tow α' packets ahead of the fatigue pre-crack before the onset of unstable fracture.<BR>Stretched zone was observed at the tip of the fatigue pre-crack, and the zone width related linearly to the critical crack opening displacement. The width of the stretched zone was increased by the enhanced relaxation of the stress concentration by the micro-cleavage nucleation after the spreading of the plastic zone over about one to two α' packets.<BR>It seemed that the enhanced blunting process of the fatigue crack led to the increment in KIC. On the other hand, KIC was independent of such a structural unit as γ grain or α' packet when the enhanced blunting effect was not introduced.

収録刊行物

  • 鉄と鋼

    鉄と鋼 64 (7), 1047-1055, 1978

    一般社団法人 日本鉄鋼協会

参考文献 (3)*注記

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ