クリープ抵抗性,Al2O3形成型オステニット型ステンレス鋼
Y Yamamoto1, M P Brady, Z P Lu
1Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge, TN 37831-6115, USA.
まとめ
新しいオステニット型ステンレス鋼は,高温性能を向上させています. これらの費用対効果の高い合金では,エネルギーアプリケーションの優れたクリープ強度と酸化耐性を提供します.
科学分野:
- マテリアルサイエンス 材料科学
- メタルルジーは,金属の製造業です.
- 高温合金 高温合金
背景:
- 高温アプリケーションのための高度な材料の開発は,エネルギー変換効率と部品の寿命の改善に不可欠です.
- 既存の高強度鋼は,攻撃的な酸化環境や高温下での使用が制限されていることが多い.
- アウステニット型ステンレス鋼は,機械性能が好ましいが,極端な条件では改良が必要である.
研究 の 目的:
- 保護用アルミニウム (Al2O3) スケールを形成できる費用対効果の高い,高クリープ強度のオステニット型ステンレス鋼の新しいファミリーを開発する.
- エネルギー変換システムを要求する構造部品のより高い動作温度を可能にするために.
- 特定の合金元素が爬行抵抗性および酸化行動に及ぼす影響を調査する.
主な方法:
- Fe-20Ni-14Cr-2.5Al (重量パーセント) の組成に基づいた合金設計.
- 強化は,炭化ニオビウム (NbC) のナノ分散によって達成されます.
- Al2O3のスケール形成を促進し,オステニットマトリックスを安定させるために,チタンとヴァナジウムを除去する.
- 様々な高温条件下でのクリープ破裂寿命と酸化抵抗の試験.
主要な成果:
- 750°C,100MPaの空気で2000時間を超えるクリープ・ブレイク寿命が実証されています.
- 以前の合金と比較してアルミニウム含有量が減少した保護性Al2O3スケール形成を達成しました.
- 650°Cと800°Cの両方で10%の水蒸気を含む空気中の酸化に対する耐性を示した.
- アウステニットマトリックス構造の安定化が確認されました.
結論:
- 開発された安価で,Al2O3を形成するオステニット型ステンレス鋼は,優れたクリープ強度と酸化耐性を示しています.
- これらの合金には,エネルギー変換システムの構造部品の動作温度を上昇させる大きな可能性があります.
- 最適な合金組成,特にAlの減少とTi/Vの除去は,優れた高温性能を達成するための鍵です.
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