Effect of Interpass Time and Cooling Rate on Apparent Activation Energy for Hot Working and Critical Recrystallization Temperature of Nb-microalloyed Steel

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著者

    • RADOVIC Nenad
    • Department of Physical Metallurgy, Faculty of Technology and Metallurgy, University of Belgrade
    • DROBNJAK Djordje
    • Department of Physical Metallurgy, Faculty of Technology and Metallurgy, University of Belgrade

抄録

Two-stage linear ln[sinh(ασ)] <I>vs.</I> 1/<I>T</I> relations indicative of double <I>Q</I><sub>HW</sub> behavior, are obtained from anisothermal multipass flow curves generated by testing Nb/Ti microalloyed steel in torsion (in the range 1250-800ºC), except for the case of the high cooling rate-short interpass time tests, which gave rise to single-stage plots, indicative of single <I>Q</I><sub>HW</sub> behavior. Above the <I>T</I><sub>nr</sub>, the <I>Q</I><sub>HW</sub><sup>U</sup> (apparent activation energy for hot working corresponding to the upper temperature range) is little affected by test variables (interpass time and cooling rate) and type of deformation (isothermal continuous and anisothermal multipass deformation give virtually equivalent <I>Q</I><sub>HW</sub><sup>U</sup>, values above the <I>T</I><sub>nr</sub>). However, below the <I>T</I><sub>nr</sub>, the <I>Q</I><sub>HW</sub><sup>L</sup>, corresponding to the lower temperature range, becomes sensitive to test variables, and may show considerable deviation from <I>Q</I><sub>HW</sub><sup>L</sup> obtained in continuous tests. Therefore, the temperature dependence of the flow stress, below the <I>T</I><sub>nr</sub>, relevant to a multipass hot working operation, can be well described only by the <I>Q</I><sub>HW</sub><sup>L</sup> obtained from the multipass flow curves, because it is interpass time dependent. The interpass time dependence of both the <I>Q</I><sub>HW</sub><sup>L</sup> and the <I>T</I><sub>nr</sub> can be divided into three regions. Within the short interpass time region (1.8 to 10 sec), the two parameters show opposite trends, while beyond 10 sec they correlate well. Within the 1.8 to 10 sec region the <I>T</I><sub>nr</sub> is assumed to be controlled by Nb in solid solution, while the <I>Q</I><sub>HW</sub><sup>L</sup> is controlled by both solute and precipitation effect. Beyond 10 sec precipitation is the only controlling mechanism. In addition to the <I>T</I><sub>nr</sub> derived from Mean Flow Stress (MFS) and ln[sinh(ασ)] <I>vs</I>. 1/<I>T</I> plots, the recrystallization limit, <I>T</I><sub>rl</sub>, which correlates well with both <I>T</I><sub>nr</sub>'s, and the recrystallization stop, <I>T</I><sub>rs</sub>, temperatures are derived from % Fractional Softening (FS) <I>vs.</I> 1/<I>T</I> plots.

収録刊行物

  • ISIJ international

    ISIJ international 39(6), 575-582, 1999-06-15

    The Iron and Steel Institute of Japan

参考文献:  30件中 1-30件 を表示

  • <no title>

    TANAKA T.

    Microalloying75 107, 1975

    被引用文献1件

  • <no title>

    SELLARS C. M.

    Acta Metall. 14, 1136, 1966

    被引用文献3件

  • <no title>

    ROBERTS W.

    Processing and Structure 111, 1984

    被引用文献1件

  • <no title>

    ROBERTS W.

    ICSMA 7 2, 1859, 1986

    被引用文献1件

  • <no title>

    OVERDAL H. O.

    ICSMA 7 2, 1037, 1986

    被引用文献1件

  • <no title>

    BARAGAR D. L.

    J. Mech. Work. Technol. 14, 295, 1987

    被引用文献1件

  • <no title>

    DEVADAS C.

    Metall. Trans. A 22A, 321, 1991

    被引用文献1件

  • <no title>

    JONAS J. J.

    Future Developments of Metals and Ceramics 147, 1992

    被引用文献2件

  • <no title>

    BROBNIJAK DJ.

    Steel Res. 68, 306, 1997

    被引用文献1件

  • <no title>

    BAI D. Q.

    Processing Microstructure and Properties of Microalloyed and Other Low Alloy Steels 165, 1991

    被引用文献1件

  • <no title>

    BAI D. Q.

    Metall. Trans. A 24A, 2151, 1993

    被引用文献12件

  • <no title>

    BAI D. Q.

    34th MWSP Conf. Proc. 515, 1993

    被引用文献1件

  • <no title>

    DUTTA B.

    Mater. Sci. Technol. 2, 146, 1986

    被引用文献1件

  • <no title>

    DUTTA B.

    Materi. Sci. Technol. 3, 197, 1987

    被引用文献1件

  • <no title>

    SIWECKI T.

    33rd MWSPCP 34, 397, 1992

    被引用文献1件

  • <no title>

    DROBNIJAK DJ.

    Recrystallization '92 113-115, 411, 1993

    被引用文献1件

  • <no title>

    YUE S.

    Mater. Forum 14, 245, 1990

    被引用文献2件

  • <no title>

    LIU W. J.

    Can. Metall. Q. 26, 145, 1987

    被引用文献2件

  • <no title>

    BARRACLOUGH D. R.

    Met. Sci. 13, 257, 1979

    被引用文献8件

  • <no title>

    KWON O.

    Acta Metall Mater. 39, 529, 1991

    被引用文献7件

  • <no title>

    LAASRAOUI A.

    Metall. Trans. A 22A, 151, 1991

    被引用文献9件

  • <no title>

    CUDDY L. J.

    Thermomechanical Processing of Microalloyed Austenite 129, 1982

    被引用文献1件

  • <no title>

    CUDDY L. J.

    Metall. Trans. A 12A, 1313, 1981

    被引用文献5件

  • <no title>

    KASPAR R.

    Steel Res. 58, 271, 1987

    被引用文献1件

  • <no title>

    BORATTO F.

    THERMEC-88 1, 383, 1988

    被引用文献2件

  • <no title>

    SANKAR J.

    Met. Technol. 6, 325, 1979

    被引用文献1件

  • <no title>

    DUTTA B.

    Acta Metall. Mater. 40, 653, 1992

    被引用文献5件

  • <no title>

    BUFFINGTON F. S.

    Acta Metall. 9, 434, 1961

    被引用文献8件

  • Proc. of Int. Conf. Recrystallization 92

    SUN W. P.

    Mater. Sci. Forum 113-115, 533, 1993

    被引用文献2件

  • <no title>

    LAASRAOUI A.

    Metall. Trans. A 22A, 1545, 1991

    DOI 被引用文献17件

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