Grain refinement in a plain carbon steel under intercritical warm deformation was studied by torsion tes ring. Based on the experimental results, the warm flow behaviour and microstructural evolution of ferrite were researched with particular emphasis on the effect of the strain rate in controlling the grain refinement mechanism of fer- rite. The deformed microstructures were investigated at various strain rates using optical microscopy and electron back-scattered diffraction （EBSD）. The EBSD observations indicate that an increase in the strain rate leads to the development of new fine ferrite grains with high angle boundaries. Furthermore, it shows that the annihilation of dislo- cations occurs more readily at lower strain rate. The elongated ferrite grains continuously dynamically recrystallize to form the equiaxed fine ferrite grains. Thereby, the aspect ratio of elongated grains decreases with increasing the strain rate. Furthermore, the peak stress and steady state stress of ferrite both increase with increasing strain rate. Based on the study, the effect of strain rate on the development of fine ferrite grains during continuous dynamic recrystallization of ferrite was analyzed in detail.
参考文献
| [1] | Fernandez A I;Uranga P;Lopez B et al.Dynamic Recrystal- lization Behavior Covering a Wide Austenite Grain Size Range in Nb and Nb-Ti Microalloyed Steels[J].Mater Se Eng,2003,361A(1/2):367. |
| [2] | McQueen H J;Yue S;Ryan N D et al.Hot Working Charac- teristics of Steels in Austenitic State[J].Journal of Materials Processing Technology,1995,53(1/2):293. |
| [3] | Jonas J J .Dynamic Rrecrystallization-Scientific Curiosity or In- dustrial Tools[J].Materials Science and Engineering,1994,184A(02):155. |
| [4] | P.D.Hodgson;M.R.Hickson;R.K.Gibbs .ULTRAFINE FERRITE IN LOW CARBON STEEL[J].Scripta materialia,1999(10):1179-1184. |
| [5] | Yada H;Li C M;Yamagata H .Dynamic 7--a Transformation During Hot Deformation in Iron-Nickel-Carbon Alloys[J].ISIJ International,2000,40(02):200. |
| [6] | Zhongmin YANG;Ruizhen WANG .Formation of Ultra-fine Grain Structure of Plain Low Carbon Steel through Deformation Induced Ferrite Transformation[J].ISIJ International,2003(5):761-766. |
| [7] | Beladi H;Kelly G L;Shokouhi A et al.The Evolution of UI- trafine Ferrite Formation Through Dynamic Strain-Induced Transformation[J].Materials Science and Engineering,2004,371A(1/2):343. |
| [8] | Hurley P J;Muddle B C;Hodgson P D .The Production of U1- trafine Ferrite During Hot Torsion Testing of a 0.11 Wt Pct C Steel[J].Metali Mater Trans,2002,33A(09):2985. |
| [9] | Najafi Zadeh A;Jonas J J;Yue S .Grain Refinement by Dy- namic Recrystallization During the Simulated Warm Rolling of Interstitial Free Steels[J].Metallurgical and Materials Transactions,1992,23A(09):2607. |
| [10] | L. Storojeva;D. Ponge;R. Kaspar .Development of microstructure and texture of medium carbon steel during heavy warm deformation[J].Acta materialia,2004(8):2209-2220. |
| [11] | Song R;Ponge D;Raabe D;Kaspar R .Microstructure and crystallographic texture of an ultrafine grained C-Mn steel and their evolution during warm deformation and annealing[J].Acta materialia,2005(3):845-858. |
| [12] | A. Belyakov;K. Tsuzaki;H. Miura .Effect of initial microstructures on grain refinement in a stainless steel by large strain deformation[J].Acta materialia,2003(3):847-861. |
| [13] | S. Gourdet;F. Montheillet .A model of continuous dynamic recrystallization[J].Acta materialia,2003(9):2685-2699. |
| [14] | Eghbali B;Abdollah Zadeh A;Beladi H et al.Characteriza tion on Ferrite Mierostructure Evolution During Large Strain Warm Torsion Testing of Plain Low Carbon Steel[J].Materials Science and Engineering,2006,435-436A:499. |
| [15] | Jazaeri H;Humphreys F J .The Transition From Discontinu ous to Continuous Recrystallization in Some Aluminium A1 loys:lI Annealing Behavior[J].Acta Materialia,2004,52(11):3251. |
| [16] | A. Belyakov;T. Sakai;H. Miura .Continuous recrystallization in austenitic stainless steel after large strain deformation[J].Acta materialia,2002(6):1547-1557. |
| [17] | Hodgson P D;Collinson D C;Perett B.The Use of Hot Tor- sion to Simulate the Thermomechanical Processing of Steel[A].Tsuku ba:Dynamic Systems Inc and NRIM,1997:219. |
| [18] | Sugden A A B;Bhadeshia H K D H .Thermodynamic Estima tion of Liquidus,Solidus,Aoa Temperatures,and Phase Corn positions for Low Alloy Multicomponent Steels[J].Mater Sc Technol,1989,5(10):977. |
| [19] | H. Beladi;G. L Kelly;P. D. Hodgson .Microstructural evolution of ultrafine grained structure in plain carbon steels through single pass rolling[J].Materials Science and Technology: MST: A publication of the Institute of Metals,2004(12):1538-1544. |
| [20] | Hirata T.;Mukai T.;Saito N.;Tanabe S.;Kohzu M.;Higashi K. .Experimental prediction of deformation mechanism after continuous dynamic recrystallization in superplastic P/M7475[J].Journal of Materials Science,2003(19):3925-3932. |
| [21] | A. BELYAKOV .Grain Refinement Under Multiple Warm Deformation in 304 TypeAustenitic Stainless Steel[J].ISIJ International,1999(6):592-599. |
| [22] | H.J. McQUEEN .Elevated-Temperature Deformation at Forming Rates of 10~(-2) to 10~2s~(-1)[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,2002(2):345-362. |
| [23] | McQueen H J;Blum W .Dynamic Recovery:Sufficient Mech anism in the Hot Deformation of A1(99.99)[J].Materials Science and Engineering,2000,290A(1/2):95. |
| [24] | Saiji M;Kei S;Susumu S et al.Effect of Hot Rolling Strain Rate in the Ferrite Region on the Recrystallization Texture of Extra LowCSheet Steels[J].ISIJ International,1994,34(01):77. |
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