金属学报  1978, Vol. 14 Issue (4): 323-460

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Fe-0.04Nb-0.02C合金的强化

林栋梁

上海交通大学

STRENGTHENING OF THE Fe-0.04Nb-0.02C ALLOY

Lin Dong-liang (Lin Tung-liang) (Shanghai Jiaotong University)

林栋梁. Fe-0.04Nb-0.02C合金的强化[J]. 金属学报, 1978, 14(4): 323-460.
. STRENGTHENING OF THE Fe-0.04Nb-0.02C ALLOY[J]. Acta Metall Sin, 1978, 14(4): 323-460.

摘要 参考文献 相关文章 Metrics 全文: PDF(10604 KB)   摘要: Fe-0.04Nb-0.02C合金经1175—900℃轧制并随即在600℃等温处理后,获得直径为7—22微米等轴细晶粒的α-Fe。在α-Fe中保留相当数量的三维和二维位错网络,并沉淀析出细小的NbC粒子。通过细化晶粒,NbC第二相粒子和位错亚结构的综合强化,合金下屈服强度可提高到35—38公斤/毫米~2。下屈服强度σ_(1y)与晶粒的平均直径d之间的关系符合Hall-Petch公式: σ_(1y)=σ_i+k_yd~(-(1/2)) 其中k_y=2.2公斤/毫米~(3/2);对于600℃等温30秒,40分及3小时者,σ_i分别为21.5,13.5及13.5公斤/毫米~2。理论计算结果表明,σ_i值是NbC第二相粒子弥散强化,位错亚结构强化和点阵阻力对屈服强度贡献σ_p,σ_d和σ_1的叠加,即 σ_i=σ_p+σ_d+σ_1 合金的位错密度随拉伸变形程度的增高而增加。平均位错密度ρ与对应的流变应力值σ_f的关系可表达成下式 σ_f=σ_0+αGbρ~(1/2) 其中α=0.37;σ_0是除位错交互作用外其他因素对流变应力的贡献,对于600℃等温30秒,40分和3小时者,σ_0分别为34,30及30公斤/毫米~2。 在α-Fe中沉淀析出的NbC粒子周围观察到“沉淀生长”位错圈,对其形成机理进行了分析,它们的强化作用尚需进一步探明。 Abstract：By hot roiling at temperatures between 1175—900℃ and subsequently isothermal treating at 600℃, the grain size of α-Fe was refined to 7—22μm in diameter. There were a number of 3-and 2-dimensional dislocation networks and precipitates of small NbC particles in α-Fe. The lower yield stress of the alloy can be increased up to 35—42 kg/mm~2 by the combined strenthening of grain refinement, second phase particle (NbC) and dislocation substructure. The lower yield stress σ_(1y) is related to the average value of the grain diameter by Hall-Perch equation:σ_(ly)=σ_i+k_yd~(1/2) where k_y is proportional constant of strengthening by grain refinement, k_y=2.2 kg/mm~(3/2); σ_i is friction stress on moving dislocations in grains. The values of σ_i for the specimens isothermal treated for 30 see, 40 rain and 3 hr at 600℃ are 21.5, 13.5 and 13.5 kg/mm~2 respectively.The dislocation density in the alloy is increased with increasing deformation. The relationship between the square root of average dislocation density and the flow stress can be expressed in the form of the following equation:σ_f=σ_0 +αGbρ~(1/2) where G is the shear modulus; b is the magnitude of the Burgers vector;α is the strengthening proportional constant by the interaction of dislocations, α=0.37;σ_0 is the flow stress due to all cases (e. g. grain refinement and dispersion strengthening etc. ) other than dislocation interaction. With the specimens isothermal treated at 600℃ for 30 see, 40 rain and 3hr, the values of σ_0 are found to be 34, 30 and 30 kg/mm~2 respectively. Results from the analysis of experimental data and theoretical calculations have shown that the value of σ_i is the summation of the contribution to yield stress by the dispersion strengthening of second phase particle (NbC)σ_p, dislocation substructure strengthening σ_d and lattice friction stress σ_1, i. e.σ_i=σ_p+σ_d+σ_1The "precipitate growth"dislocation loops have been observed around the NbC particles precipitated in α-Fe. The mechanisms for "precipitate growth" dislocations have been discussed in this paper, but their effect on the strengthening has not yet been clarified and will be further investigated. 收稿日期: 1978-04-18      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 林栋梁 44.8K 链接本文: https://www.ams.org.cn/CN/      或      https://www.ams.org.cn/CN/Y1978/V14/I4/323 [1] Morrison, W. B. and Woodhead, J. H., J. Iron Steel Inst., London, 201 (1963) , 43． [2] Morrison, W. B., J. Iron Steel Inst., London, 201 (1963) , 317． [3] Gray, J. M. et al., J. Iron Steel Inst., London, 203 (1965) , 812． [4] Gray, J. M. and Yeo, R. B. G., ASM Trans. Quart., 61 (1968) , 255． [5] Duekworth, W. E. and Baird, J. D., J. Iron Steel Inst., London. 207 (1969) , 854． [6] Processing and Properties of Low Carbon Steel, TMS-AIME, New York, 1973． [7] The Proceedings of the Conference "Microalloying 75" , Washington, D. C., Sept., 1975． [8] Lin, T. L. (林栋梁) and McLean, D., Metal Sci. J., 2 (1968) , 108． [9] Ham, R. K., Phil. Mag., 6 (1961) , 1183． [10] Silcock, J. M., J. Iron Steel Inst., London, 201 (1963) , 409． [11] Duwez, P. and Odell, F., J. Electrochem.. Soc., 97 (1950) , 299． [12] Calm. J. W. and Nutting, J., Trans. AIME, 215 (1959) , 526． [13] Dingley, D. J. and McLean, D., Acta Met., 15 (1967) , 885． [14] Keh, A. S. and Weissman, S., Eleetron Microscopy and Strength of Crystals, Ed. by G. Tho mas and J. Washburn, Wiley, New York, 1963, p. 231． [15] Tekin, E. and Kelly, P. M., Precipitation from Iron-Base Alloys, Eds. by G. R. Speieh and J. B. Clark, Gordon and Breach, New York, 1963, p. 173． [16] Manual on Electron Metallography Techniques, Amer. Soe. Test. Mater., Spec. Tech. Publ., № 547, 1973． [17] Mondino, M. and Seeger, A., Scripta Met., 11 (1977) , 817． [18] Orowan, E., Symposium on Internal Stresses in Metals and Alloys, Institute of Metals, London, 1948, p. 451． Dislocations in Metals, Ed. by M. Cohen, AIMME, 1954, p. 131． [19] Ashby, M. F., Oxide Dispersion Strengthening, Ed. by G. S. Ansell, T. D. Cooper and F. V. Lenel, Gordon and Breach, New York, 1968, p. 143． [20] Ashby, M., Z. Metallk., 55 (1964) , 5． No related articles found! Viewed Full text Abstract Cited   Shared      Discussed