University of Oulu

J Hannula et al 2019 J. Phys.: Conf. Ser. 1270 012018. https://doi.org/10.1088/1742-6596/1270/1/012018

The effect of microalloying elements on prior austenite grain growth of low-carbon slab material

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Author: Hannula, J1; Kaijalainen, A1; Porter, D1;
Organizations: 1Materials and Mechanical Engineering, Centre for Advanced Steels Research, FI-90014 University of Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 8.6 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2019081924667
Language: English
Published: IOP Publishing, 2019
Publish Date: 2019-08-19
Description:

Abstract

The effect of microalloying elements on the prior austenite grain growth of slab materials during slab reheating has been investigated. The investigated materials were laboratory castings with two levels of carbon (0.05 and 0.09 wt.%) and different combinations of microalloying elements, such as V, Nb, Mo and Ti. Experimental results were compared to equilibrium Thermo-Calc® simulations predicting the solubility of different precipitates during slab reheating. Based on slab reheating experiments at temperatures between 1100–1250 °C, Ti is the only alloying element to hinder prior austenite grain growth effectively above 1200 °C. For the steel containing high carbon with Nb, V and Ti microalloying, the average prior austenite grain size was less than 50 μm after the slab reheating to 1250 °C, which can be considered very small. According to Thermo-Calc® calculations, stable Ti(CN) precipitates are formed from the liquid and are in solution until 1500 °C. Until 50–60% of soluble NbC -precipitates, austenite grain size remained relatively small in Nb-alloyed compositions without Ti, but after that grain size increased drastically. For only V-alloyed steels, already at the soaking temperature of 1100 °C hardly any VC precipitates exists based on Thermo-Calc® simulations, and after that grain coarsening can be assumed to be controlled only by the coarsening rate of austenite grains.

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Series: Journal of physics. Conference series
ISSN: 1742-6588
ISSN-E: 1742-6596
ISSN-L: 1742-6588
Volume: 1270
Article number: 012018
DOI: 10.1088/1742-6596/1270/1/012018
OADOI: https://oadoi.org/10.1088/1742-6596/1270/1/012018
Host publication: 7th International Conference on Recrystallization and Grain Growth, 4–9 August 2019, Ghent, Belgium
Conference: International Conference on Recrystallization and Grain Growth
Type of Publication: A4 Article in conference proceedings
Field of Science: 218 Environmental engineering
Subjects:
Funding: The financial support of CBMM (Companhia Brasileira de Metalurgia e Mineracao) and SSAB Europe Oy is gratefully acknowledged.
Copyright information: Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd.
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