Zhou, T.; O’Malley, R.J.; Zurob, H.S.; Subramanian, M.; Cho, S.-H.; Zhang, P. Control of Upstream Austenite Grain Coarsening during the Thin-Slab Cast Direct-Rolling (TSCDR) Process. Metals2019, 9, 158.
Zhou, T.; O’Malley, R.J.; Zurob, H.S.; Subramanian, M.; Cho, S.-H.; Zhang, P. Control of Upstream Austenite Grain Coarsening during the Thin-Slab Cast Direct-Rolling (TSCDR) Process. Metals 2019, 9, 158.
Zhou, T.; O’Malley, R.J.; Zurob, H.S.; Subramanian, M.; Cho, S.-H.; Zhang, P. Control of Upstream Austenite Grain Coarsening during the Thin-Slab Cast Direct-Rolling (TSCDR) Process. Metals2019, 9, 158.
Zhou, T.; O’Malley, R.J.; Zurob, H.S.; Subramanian, M.; Cho, S.-H.; Zhang, P. Control of Upstream Austenite Grain Coarsening during the Thin-Slab Cast Direct-Rolling (TSCDR) Process. Metals 2019, 9, 158.
Abstract
Thin Slab Casting and Directing Rolling (TSCDR) has become a major process for flat- rolled production. However, the elimination of slab reheating and limited number of thermomechanical deformation passes leave fewer opportunities for austenite grain refinement resulting in some large grains persist in the final microstructure. In order to achieve excellent Ductile to Brittle Transaction (DBTT) and Drop Weight Tear Test (DWTT) properties in thicker gauge high strength low alloy products, it is necessary to control austenite grain coarsening prior to the onset of thermomechanical processing. This contribution proposes a suite of methods to refine the austenite grain from both theoretical and practical perspective including: increasing cooling rate during casting, liquid core reduction, increasing austenite nucleation sites during the delta ferrite to austenite phase transformation, controlling holding furnace temperature and time to avoid austenite coarsening, and producing new alloy with two phase pinning to arrest grain coarsening. These methodologies can not only refine austenite grain size in the slab center, but also improve the slab homogeneity.
Keywords
thin slab casting direct rolling, austenite grain coarsening, grain growth control, liquid core reduction, secondary cooling, two phase pinning
Subject
Chemistry and Materials Science, Metals, Alloys and Metallurgy
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
