(1. 北京科技大學(xué) 鋼鐵冶金新技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100083；
2. 北京科技大學(xué) 冶金與生態(tài)工程學(xué)院，北京 100083)
摘 要: 通過(guò)熱力學(xué)計(jì)算研究稀土Ce夾雜物在高鐵扣件彈簧鋼中生成的熱力學(xué)條件，并分析加入稀土Ce對(duì)Al2O3夾雜的變質(zhì)作用及條件。由稀土Ce硫化物、氧化物和氧硫化物的標(biāo)準(zhǔn)吉布斯生成自由能構(gòu)建了稀土Ce夾雜物的空間析出圖, 并將其應(yīng)用在預(yù)測(cè)高鐵扣件彈簧鋼中加入稀土Ce后夾雜物的生成順序，并確定其存在形式及熱力學(xué)轉(zhuǎn)換條件。計(jì)算結(jié)果表明：鋼液中加入稀土最容易生成的是CeAlO3夾雜，其次是Ce2O2S；在本計(jì)算所用鋼種的氧活度和硫活度分別為0.000 639和0.005 845的條件下，鋼液中首先會(huì)析出Ce2O2S；當(dāng)鋼液中Al含量為0.013%時(shí)，稀土變質(zhì)Al2O3夾雜的理論加入量為0.001 9%。
關(guān)鍵字: 熱力學(xué)；稀土；夾雜物；彈簧鋼；高鐵扣件
（1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Metallurgical and Ecological Engineering, University of Science a）
Abstract:Thermodynamic condition of rare earth cerium inclusion formed in spring steel used in fastener of high-speed railway was studied by the thermodynamic calculation. In addition, the effect and condition of rare earth cerium on modifying Al2O3 inclusion were analyzed. Through the standard Gibbs free energies of formation of the sulfides, oxides and oxysulfides of cerium, the precipitation diagram in space was built. And it was applied to predict the sequence of rare earth inclusion formed the spring steel. Finally, the ultimate state of rare earth inclusions and their thermodynamic transformation condition were determined. The computation results show that the most easily formed inclusion is CeAlO3 when rare earth element Ce is added to the molten steel, with Ce2O2S following. In this work, when the activities of oxygen and sulfur in the steel are 0.000 639 and 0.005 845, respectively, the first precipitated inclusion is Ce2O2S. Moreover, when the aluminum content in the steel is 0.013%, the theoretic amount of added rare earth Ce is 0.0019%, which can realize Al2O3 deformation.
Key words: thermodynamics; rare earth; inclusion; spring steel; fastener of high-speed railway
