scholarly journals Modeling of Austenite Grain Size Distribution in Nb Microalloyed Steels Processed by Thin Slab Casting and Direct Rolling (TSDR) Route

2004 ◽  
Vol 44 (8) ◽  
pp. 1416-1425 ◽  
Author(s):  
P. Uranga ◽  
A. I. Fernández ◽  
B. López ◽  
J. M. Rodriguez-Ibabe
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Microalloyed Steels ◽  
Thin Slab ◽  
Austenite Grain Size ◽  
Thin Slab Casting ◽  
Austenite Grain ◽  
Slab Casting ◽  
Direct Rolling

scholarly journals Vanadium Microalloyed Steel for Thin Slab Casting and Direct Rolling

2005 ◽  
Vol 500-501 ◽  
pp. 237-244 ◽  
Author(s):  
Yu Li ◽  
T.N. Baker
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Grain Structure ◽  
High Yield ◽  
Microalloyed Steels ◽  
Dispersion Strengthening ◽  
Thin Slab ◽  
Thin Slab Casting ◽  
Slab Casting ◽  
Direct Rolling

Vanadium microalloyed steels with high yield strength (»600MPa), good toughness and ductility have been successfully produced in commercial thin slab casting plants employing direct rolling after casting. Because of the high solubility of VN and VC, most of the vanadium is likely to remain in solution during casting, equalisation and rolling. While some vanadium is precipitated in austenite as cuboids and pins the grain boundaries, a major fraction is available for dispersion strengthening of ferrite. Despite a coarse as-cast grain size, significant grain refinement can be achieved by repeated recrystallisation during hot rolling. Consequently, a fine and uniform ferrite grain structure is produced in the final strip. Increasing the V and N levels increases dispersion strengthening which occurs together with a finer ferrite grain size. The addition of titanium to a vanadium containing steel, decreases the yield strength due to the formation of V-Ti(N) particles in austenite during both casting and equalisation. These large particles reduced the amount of V and N available for subsequent precipitation of fine (~5nm) V rich dispersion strengthening particles in ferrite.

scholarly journals Local Austenite Grain Size Distribution in Hot Bar Rolling of AISI 4135 Steel

2005 ◽  
Vol 45 (5) ◽  
pp. 706-712 ◽  
Author(s):  
Ho-Won LEE ◽  
Hyuck-Cheol KWON ◽  
Yong-Taek IM ◽  
P. D. HODGSON ◽  
S. H. ZAHIRI
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Austenite Grain Size ◽  
Bar Rolling ◽  
Austenite Grain

Modeling the Effect of Austenite Grain Size Distribution on Austenite Decomposition Kinetics

2007 ◽  
pp. 4584-4589
Author(s):  
Andrej Samoilov ◽  
Yuri Titovets ◽  
Nikolay Zolotorevsky ◽  
Gottfried Hribernig ◽  
Andreas Pichler
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Decomposition Kinetics ◽  
Austenite Decomposition ◽  
Austenite Grain Size ◽  
Austenite Grain

scholarly journals Control Upstream Austenite Grain Coarsening during Thin Slab Casting Direct Rolling (TSCDR) Process

2019 ◽  
Author(s):  
Tihe Zhou ◽  
Ronald J. O'Malley ◽  
Hatem S. Zurob ◽  
Mani Subramanian ◽  
Sang-Hyun Cho ◽  
...  
Keyword(s):  
Thermomechanical Processing ◽  
Liquid Core ◽  
Thin Slab ◽  
Delta Ferrite ◽  
Two Phase ◽  
Austenite Grain Size ◽  
Grain Coarsening ◽  
Thin Slab Casting ◽  
Austenite Grain ◽  
Slab Casting

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.

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