Grain Size Modeling during Hot Rolling of a Nb Microalloyed Steel Beam

Abstract:

Hot rolling of beams is carried out essentially in two stages. Roughing is performed in a reversing mill at temperatures in the range of 1100 oC, at relatively low strain rates and with long interpass times. Finishing is carried out in a reversing two stand mill at temperatures in between 1000 and as low as 700 oC considering parts of the web in the last passes. Strain rates are moderate and interpass times are in the range of 5 to 20s. There is, therefore, as it can be seen from the description just made of the rolling schedule, a fair resemblance to deformation in plate mills. Technology for themomechanical processing, TMP, of plates is very well known and disseminated. Application of this technology to beam rolling is, on the other hand, rather seldom known of. This paper addresses an application of TMP plate technology to beam rolling. In particular, austenite grain size evolution is examined. The usage of Nb microalloyed steels to this process is discussed in terms of possible beneficial effects to ferrite grain refinement.

• Periodical: Materials Science Forum (Volume 753)
• Pages: 397-402
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.753.397
• Online since: March 2013
• Authors: Emanuelle Garcia Reis, Ronaldo Barbosa
• Keywords: Grain Growth, Hot Rolling of Beams, Nb Microalloyed Steel, Precipitation, Recrystallization

References

[1] C.M. Sellars, In Hot working and forming processes, C.M. Sellars and G. Davies eds., London, 1980, 3-15.

[2] J.H. Beynon and C. M. Sellars, Modelling microstructure and effects during hot rolling. ISIJ Int. 32 (1991) 359-367

DOI: 10.2355/isijinternational.32.359

[3] P. D. Hodgson and R. K. Gibbs, A mathematical model to predict the mechanical properties of hot rolled C-Mn and microalloyed steels. ISIJ Int.. 32 (1992) 1329-1338

DOI: 10.2355/isijinternational.32.1329

[4] F. Siciliano Jr., K. Minami, T. M. Maccgno and J. J. Jonas, Mathematical modelling of the mean flow stress, fractional softening and grain size during the hot strip rolling of C-Mn steels. ISIJ Int. 36 (1996) 1500-1506

DOI: 10.2355/isijinternational.36.1500

[5] K. Minami, F. Siciliano Jr., T.M. Maccagno and J. J. Jonas, Mathematical modelling of the mean flow stress during hot strip rolling of Nb steels. ISIJ Int. 36 (1996) 1507-1515

DOI: 10.2355/isijinternational.36.1507

[6] T. M. Maccagno, J. J. Jonas and P. D. Hodgson, Spreadsheet modeling of grain size evolution during rod rolling. ISIJ Int. 36 (1996) 720-728.

DOI: 10.2355/isijinternational.36.720

[7] D. Q. Bai, S. Yue, T. Maccagno and J. J. Jonas, Static recrystalization of Nb and Nb-B steels under continuous cooling conditions. ISIJ Int. 36 (1996) 1084-1093.'

DOI: 10.2355/isijinternational.36.1084

[8] J.S. Liu, J. Yanagimoto, Three-dimensional numerical analysis of microstructural evolution in and after bar and shape rolling processes. ISIJ Int. 42 (2002) 868-875.

DOI: 10.2355/isijinternational.42.868