Influence of Oxide Particles and Residual Elements on Microstructure and Toughness in the Heat-Affected Zone of Low-Carbon Steel Deoxidized with Ti and Zr
スポンサーリンク
概要
- 論文の詳細を見る
The microstructure and toughness in Fe–0.04%C–1.85%Mn–0.03%Si–0.018%Nb steel deoxidized with Ti and Zr have been studied as functions of particle characteristics, austenite grain size and soluble Ti and Zr contents using a simulated HAZ (heat affected zone) thermal cycle (peak temperature, 1400°C; peak holding time, 60 s; time of cooling from 800 to 500°C, 70 s) and submerged arc welding (heat input of 15 kJ/mm), respectively. Microstructures were studied in samples containing 1.0 to 1.5 μm-diameter oxide particles numbering 500 to 2000 mm–2 and with a soluble oxygen content of 10 to 30 ppm (measured before casting) and soluble Ti and Zr contents of 50–150 ppm. The γ grain size after HAZ thermal cycle in the range between 200 and 600 μm is controlled by pinning and solute drag. Small γ grain size below 300 μm was obtained with high soluble Ti and Zr contents of 110–160 ppm, whereas large γ grain size above 300 μm was obtained with low soluble Ti and Zr contents of 60–110 ppm. Two types of microstructures that showed high Charpy absorbed energy (VE(–10°C)= 150–250 J and VE(–50°C)= 50–150 J) were observed independent of γ grain size: One is acicular ferrite and a small amount of grain boundary ferrite (GBF) and ferrite side plate (FSP) and the other is GBF, FSP and granular bainitic ferrite. It was observed that low VE(T) values are attributed to the formation of porosity, large-size particles, carbides (+nitrides) and lathe bainitic ferrite.
論文 | ランダム
- 規則制定の司法審査の基準--Chevron,U.S.A.,Inc.,v.Natural Resources Defense Council.Inc.,104 S.Ct.2778(1984) (アメリカ連邦最高裁公法判例の動向(1983〜84年開廷期))
- 精神衛生法の強制入院制度をめぐる憲法問題
- この子と歩む(第226回)つながりに恵まれ自分で選んだ進路
- 抗菌加工商品の表示と購入意識について
- 第28回ポ-ラログラフィ-および電気分析化学討論会プレシンポジュウム講演要旨