金属学报  1985, Vol. 21 Issue (2): 13-24

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Fe-C合金贝氏体相变热力学(KRC模型)

徐祖耀;牟翊文

上海交通大学;上海交通大学

THERMODYNAMICS(KRC MODEL)OF THE BAINITIC TRANSFORMATION IN Fe-C ALLOYS

XU Zuyao(T.Y.Hsu);MOU Yiwen Shanghai Jiaotong University

徐祖耀;牟翊文. Fe-C合金贝氏体相变热力学(KRC模型)[J]. 金属学报, 1985, 21(2): 13-24.
, . THERMODYNAMICS(KRC MODEL)OF THE BAINITIC TRANSFORMATION IN Fe-C ALLOYS[J]. Acta Metall Sin, 1985, 21(2): 13-24.

摘要 参考文献 相关文章 Metrics 全文: PDF(818 KB)   摘要: 以改进的KRC模型决定AG~(γ→α)的方法,计算了Fe-C合金贝氏体相变可能机制:γ→α+γ_1,γ→α+Fe_3C以及γ→α(浓度相同)和α′→α_B~″(贝氏体铁素体碳浓度)+Fe_3C的相变驱动力和长大(形核)驱动力.相变驱动力以γ→α+Fe_3C为最大,γ→α+γ_1次之,γ→α最小.由奥氏体转变成同成分铁素体(γ→α)的长大驱动力远小于γ→α+γ_1的长大驱动力.在贝氏体形成温度范围内,γ→α的驱动力远小于切变机制所需的驱动力.0.1—0.55wt,%C合金在B_s温度时γ→α+γ_1的相变驱动力仅约—45Jmol~(-1).0.8wt %C合金在贝氏体形成上限温度(823K)时γ→α的相变驱动力为137Jmol~(-1),而α→α+Fe_3C的相变驱动力为-527Jmol~(-1);两者相加,即在贝氏体铁素体析出渗碳体的情况下,相变总驱动力也仅有约-390Jmol~(-1).上述结果表明,贝氏体铁素体很难以切变机制形成和长大. Abstract：By application of the improved KRC model for determination of △G~(γ→α),the total driving forces for transformation and driving forces for growth(nucle-ation)for the several possible mechanisms of the bainitic transformation in Fe-Calloys,i.e.,γ→α+γ_1,γ→α+Fe_3C and γ→α′(the same composition)and α′→Fe_3C+α_B(the composition of the bainitic ferrite)are calculated.The driving forceof γ→α+Fe_3C is the largest,followed by that of γ→α+γ_1 and that of γ→α′isthe smallest.The driving force for growth of γ→α′is far less than that of γ→α+γ_1.At the temperature range of bainite formation,the driving force for γ→α′ismuch lower than that required for shear mechanism.The driving force for trans-formation of γ→α+γ_1 in 0.1—0.55 wt-%C alloys at B_s temperature is onlyabout -45 J·mol~(-1).At the upper limit temperature of bainite formation,the driv-ing force of γ→α′in 0.8 wt-%C alloy-is about 137 J·mol~(-1),and that of α′→α_B+Fe_3C is—527 J·mol~(-1).If cementite precipitates from the bainitic ferrite,thetotal driving force,i.e.,the sum of the driving forces of the above two processesis only about -390 J·mol~(-1).The above results show that the formation of thebainitie ferrite by shear mechanism is thermodynamically impossible. 收稿日期: 1985-02-18      服务 把本文推荐给朋友 加入引用管理器 E-mail Alert RSS 作者相关文章 徐祖耀 牟翊文 44.8K 链接本文: https://www.ams.org.cn/CN/      或      https://www.ams.org.cn/CN/Y1985/V21/I2/13 1 Kaufman,L.;Radcliffe,S.V.;Cohen,M.,Decomposition of Austenite by Diffusional Processes,Eds.Zackey,V,F.;Aaronson,H.I.,Interscience,New York,1962,p.313． 2 Hehemann,R.F.,Phase Transformations,ASM,Metal Park Ohio,1970,p.397． 3 Hehemann,R.F.;Kinsman,K.R.;Aaronson,H.I.,Metall.Trans.,3(1972) ,1077． 4 Aaronson,H.I.;Hall,M.G.;Barnett,D.M.;Kinsman,K.R.Scr.Metall.,9(1975) ,705． 5 Bhadeshia,H.K.D.H.;Edmonds,D.V.,Acta Metall.,28(1980) ,1265． 6 Lacher,J.R.,Proc.Cambridge Philos.Soc.,33(1937) ,518． 7 Fowler,R.H.;Guggenhiem,E.A.,Statistical Thermodynamics,Cambridge University Press,New York,1939,p.442． 8 McLellan,R.B.;Dunn,W.W.,J.Phys.Chem.Solids,30(1969) ,2631． 9 Shiflet,G.J.;Bradley,J.R.;Aaronson,H.I.,Metall.Trans.,9A(1978) ,999． 10 Aaronson,H.I.;Domain,H.A.;Pound,G.M.,Trans.Metall.Soc.AIME,236(1966) ,753． 11 Bhadeshia,H.K.D.H.,Met.Sci.,14(1980) ,230． 12 Lobo,J.A.;Greiger,G.H.,Metall.Trans.,7A(1976) ,1347． 13 Kaufman,L.;Clougherty,E.V.;Weiss,R.J.,Acta Metall.,11(1963) ,323． 14 Mogutnov,B.M.;Tomilin,I.A.;Shvartsman,L.A.,Thermodynamics of Fe-C Alloys,Metallurgy Press,Moscow,1972,p.109． 15 Orr,R.L.;Chipman,J.,Trans.Metall.Soc.AIME,239(1967) ,630． 16 徐祖耀,马氏体相变与马氏体,科学出版社,北京,1980,p.258． 17 徐祖耀,金属材料热力学,科学出版社,北京,1981,p.279-280． 18 Bhadeshia,H.K.D.H.,Met.Sci.,16(1982) ,159． 19 Steven,W.;Haynes,A.G.,J.Iron Steel Inst,London,183(1956) ,349． 20 Hsu,T.Y.(Xu Zuyao);Chang Hongbing,Acta.Metall.,32(1984) ,343． 21 Ko,T.;Cotrell,S.A.,J.Iron Steel Inst.,London,172(1952) ,307． No related articles found! Viewed Full text Abstract Cited   Shared      Discussed