Abstract A new annealing technology has been developed in order to conduct fast steel annealing. The microstructure and texture of the Nb+Ti stabilized interstitial-free (IF) steel and high Nb-IF steel highly cold deformed to a reduction of 94.2% after ultra-rapid annealing (URA) process with heating rates approximately 300 oC/s were characterized by means of OM, TEM, EBSD and XRD. The experimental results indicate that the recrystallization process is significantly accelerated and the finish recrystallization temperature is increased after URA. Moreover, the fully recrystallization can be obtained in as short as about 0.41 s, compared with about 4 s in the conventional annealing (CA) process with heating rates approximately 20o C/s. In the fully recrystallized condition, the grain size and intensity of {445}<231> fiber in the Nb+Ti-IF steel, about 11.2 μm and 15.6, can be observed in one URA cycle, respectively. However, the grain size and intensity of {445}<231> fiber are 13.5 μm and 14.0, respectively, after the Nb+Ti-IF steel is subjected to one CA cycle. On the other hand, the URA has unapparently influence on grain size, within (11.0±0.3) μm in either one URA or one CA cycle, of the high Nb-IF steel, with about 18.0 intensity of {223}<472> fiber. Simultaneously, more random fiber can be found in one URA cycle than in one CA cycle with higher intensity of {223}<472> texture up to 23.9. The grain refining effect in either one URA or one CA cycle is attributed to the mutual interaction of nucleation density, annealing time and grain boundary migration rate.
Supported by National Natural Science Foundation of China (No.51174059) and Fundamental Research Funds for the Central Universities (Nos.110607004 and 110407003)
[1] Tiitto K M, Jung C, Wray P, Garcia C I, Deardo A J. ISIJ Int, 2004; 44: 404
[2] Ghosh P, Bhattachary B, Ray R K. Scr Mater, 2007; 56: 657
[3] Verbeken K, Kestens L, Jonas J J. Scr Mater, 2003; 48: 1457
[4] Doherty R D, Hughes D A, Humphreys F J, Jonas J J, Juul Jensen D, Kassner M E, King W E, McNelley T R, McQueen H J, Rollett A D. Mater Sci Eng, 1997; A238: 219
[5] Go J, Poole W J, Militzer M, Wells M A. Mater Sci Technol, 2003; 19: 1361
[6] Ferry M, Jones D. Scr Mater, 1998; 38: 177
[7] Salvatori I, Moore W B R. ISIJ Int, 2000; 40(Suppl): 179
[8] Atkinson M. Mater Forum, 1993; 17: 181
[9] Atkinson M. Mater Sci Eng, 1999; A262: 33
[10] Muljono D, Ferry M, Dunne D P. Mater Sci Eng, 2001; A303: 90
[11] Ferry M, Muljono D, Dunne D P. ISIJ Int, 2001; 41: 1053
[12] Reis A C C, Bracke L, Petrov R, Kaluba W J, Kestens L. ISIJ Int, 2003; 43: 1260
[13] Stockemer J, Vanden Brande P. Metall Mater Trans, 2003; 34A: 1341
[14] Hou Z Y, Xu Y B, Wu D. Chin J Mater Res, 2012; 26: 13
(侯自勇, 许云波, 吴迪. 材料研究学报, 2012; 26: 13)
[15] Deng Q, Hou Z Y, Yan J J, Li J P. J Mater Metall, 2012; 11: 38
(邓峤, 侯自勇, 燕际军, 李建平. 材料与冶金学报, 2012; 11: 38)
[16] Massardier V, Ngansop A, Fabr`egue D, Merlin J. Mater Sci Eng, 2010; A527: 5654
[17] Shi H, Atkinson M. J Northeast Univ (Nat Sci), 1989; 10: 282
(施华, Atkinson M. 东北大学学报(自然科学版), 1989; 10: 282)
[18] Hazra S S, Gazder A A, Pereloma E V. Mater Sci Eng, 2009; A524: 158
[19] Stockemer J, Van den Brande P. In: Gottstein G, Molodov D A eds., Proc 1st Int Conf on Joint, Aachen: Springer–Verlag, 2001: 1131
[20] Su Q Q, Lin D W,Wang M, Gan Q S. Shanghai Met, 2009; 31(2): 53
