Physical Metallurgy Related to the Thermomechanical Process of Hot Rolling of Nb Microalloyed Steel Beams: Prediction of Mechanical Properties

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Abstract:

The main physical metallurgy processes controlling final mechanical properties in as hot rolled steel products are basically recrystalization, grain growth, precipitation and austenite to ferrite phase transformation. Knowledge of how these processes interact during an industry hot rolling schedule is the key to understand how to obtain certain mechanical properties. This know how has been routinely applied to the manufacturing of flat products such as plates and strips. Less has been reported for non flat products. When even there are such reports, these usually do not present any comparison between predictions and industry real data. This paper addresses the case of rolling of structural beams at an industry trial. Emphasis is put on how the final mechanical properties were obtained and how they can be predicted. An ordinary microstructure model was used and then the predictions were checked by comparing them to industry data. After validation, suggestions were made for improvements in the schedule aiming at having superior mechanical properties at the end product. Austenite grain size evolution is important in defining final properties, as expected. The presence of Nb as microalloyed element can enhance such properties and its role to this particular industry process was discussed.

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Materials Science Forum (Volumes 783-786)

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986-991

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May 2014

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© 2014 Trans Tech Publications Ltd. All Rights Reserved

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

Google Scholar

[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

Google Scholar

[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

Google Scholar

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

DOI: 10.2355/isijinternational.36.720

Google Scholar

[5] 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

Google Scholar

[6] 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

Google Scholar

[7] 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

Google Scholar

[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

Google Scholar