Community Research and Development Information Service - CORDIS

Abstract

This project is aimed at investigating the surface quality improvement achievable by a fine grain size and small grain boundary precipitate within the surface and sub-surface regions by use of an alternative secondary cooling practice when casting aluminium grain refined and microalloyed peritectic steel grades. A specifically designed intense cooling unit for the intermediate thickness slab caster at Corus Tuscaloosa has allowed optimisation of the operating conditions and an improvement of both as-cast and rolled product surface quality was notes. Limited work with an intense secondary cooling was performed for Bloom 750 at Scunthorpe while laboratory and pilot plant studies have demonstrated that an intense secondary cooling to increase the amount of grain boundary ferrite requires a casting speed around 0.5 m/min resulting in a loss of production. Profil/Arbed has worked at eliminating the defects occurring on their beam blanks: internal solidification imperfections have no detrimental influence on the surface quality and mechanical properties of the finished products; longitudinal discontinuities have disappeared when using an appropriate mould powder; transverse defects were eliminated by a modification of the cooling patterns, even allowing the suppression of the residual elements limitation (Cu). CRM has worked on a metallurgical study of the hot ductility improvement achievable by a grain refining treatment and numerical modelling indicates that the feasibility is rather limited as it should combine a quenching to at least 600 °C of 10 mm of the product, a reheating of this outer layer, and a progressive decrease of this layer to reach 750-850 °C before unbending. Voest-Alpine Donawitz has worked at modifying the casting parameters for avoiding surface and subsurface cracks on the CC3 bloom caster by means of SSCT tests, temperature measurement in the primary and secondary cooling zones and a numeric model

Additional information

Authors: WALMAG G, CRM - Centre de recherches métallurgiques, Angleur (BE);SMITH A W, CORUS UK Limited, Middlesbrough (UK);MCDONALD M I, CORUS UK Limited, Middlesbrough (UK);CREUTZ R, ProfilArbed Recherches, Esch-sur-Alzette (LU);DONNAY B, ProfilArbed Recherches, Esch-sur-Alzette (LU);SORMANN A, Voest-Alpine Stahl GmbH, Loeben-Donawitz (AT)
Bibliographic Reference: EUR 21445 EN (2005), 228 pp. Euro: 35
Availability: Katalogue Number: KI-NA-21445-EN-S The paper version can be ordered online and the PDF version downloaded at: http://bookshop.eu/
ISBN: ISBN: 92-894-9694-0
Record Number: 200518383 / Last updated on: 2005-10-05
Category: PUBLICATION
Original language: en
Available languages: en