Development and Characterization of a Novel Ti-Modified High-Si Medium-Mn Steel Possessing Ultra-High Strength and Reasonable Ductility After Hot Rolling

Journal Article · Wed Aug 15 04:00:00 EDT 2018 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-018-3480-X· OSTI ID:22860347

Kisku, Nicky; Sarkar, Arnab; Ray, K. K.; Mandal, Sumantra ^[1]

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1. Indian Institute of Technology, Department of Metallurgical and Materials Engineering (India)

The present work systematically correlates the strength–ductility relationship of a Ti-Si-modified Fe-Mn-Al-C steel with its microstructural characteristics such as grain size, type and morphology of precipitates, and the transformation-induced plasticity (TRIP) effect during hot deformation. The Ti-Si-modified multicomponent steel developed through melting and casting route is subjected to thermo-mechanical processing such as hot forging (at 1373 K) and subsequent hot rolling (at 1173 K). An excellent combination of ultra-high tensile strength (UTS ~ 1700 ± 20 MPa), reasonable ductility (elongation ~ 11%) and high work hardening behavior (n ~ 0.89) is achieved in the hot-rolled specimen as compared to the hot-forged one (UTS ~ 824 ± 9 MPa, n ~ 0.07) with negligible change in the elongation. The better tensile properties of the hot-rolled specimen in contrast to the hot-forged one are due to the combined effects of grain refinement during rolling, twin–twin interactions, precipitation strengthening by mixture of hexagonal structured Ti{sub 3}(Al,Si)C{sub 2} and Mn-Al-Si-rich carbide precipitates and most significantly the enhanced TRIP effect. The lower critical resolved shear stress value of martensitic transformation instigates the TRIP effect during tensile testing which resulted in the increased hardness and strength of the hot-rolled specimen. The above observation offers a strong support to the proposition that TRIP effect is the dominant plasticity-enhancing mechanism activated during the deformation of the low-stacking fault energy (~ 12.2 mJ/m{sup 2}) Si-Ti-modified, medium-Mn multicomponent steel employed in the present investigation.

• OSTI ID: 22860347
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 8 Vol. 27; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
CARBON COMPOUNDS
COMPARATIVE EVALUATIONS
DUCTILITY
GRAIN SIZE
HARDNESS
IRON COMPOUNDS
MANGANESE COMPOUNDS
PLASTICITY
PRECIPITATION
PRESSURE RANGE MEGA PA 100-1000
ROLLING
SILICON ADDITIONS
STACKING FAULTS
STEELS
STRAIN HARDENING
STRESSES
TITANIUM ADDITIONS