High Performance Bainitic Steels

Bhadeshia, H. K. D. H.

doi:10.4028/www.scientific.net/msf.500-501.63

Cited by 109 publications

(48 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During austempering of the present steel, bainitic transformation takes place and some austenite remains. During transformation of austenite to bainite, the rejected C from bainitic ferrite becomes enriched in the untransformed austenite due to the presence of Si in the steel [17,18]. The untransformed austenite will transform to martensite or get stabilized during subsequent cooling to room temperature depending on its C content.…”

Section: Microstructurementioning

confidence: 99%

Mechanical Properties of a Bainitic Steel Producible by Hot Rolling

Rana

Chen

Haldar

et al. 2017

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

A carbide-free bainitic microstructure is suitable for achieving a combination of ultra high strength and high ductility. In this work, a steel containing nominally 0.34C-2Mn-1.5Si-1Cr (wt.%) was produced via industrial hot rolling and laboratory heat treatments. The austenitization (900°C, 30 min.) and austempering (300-400°C, 3 h) treatments were done in salt bath furnaces. The austempering treatments were designed to approximately simulate the coiling step, following hot rolling and run-out-table cooling, when the bainitic transformation would take place and certain amount of austenite would be stabilized due to suppression of carbide precipitation. The microstructures and various mechanical properties (tensile properties, bendability, flangeability, and room and subzero temperature impact toughness) relevant for applications were characterized. It was found that the mechanical properties were highly dependent on the stability of the retained austenite, presence of martensite in the microstructure and the size of the microstructural constituents. The highest amount of retained austenite (~ 27 wt.%) was obtained in the sample austempered at 375°C but due to lower austenite stability and coarser overall microstructure, the sample exhibited lower tensile ductility, bendability, flangeability and impact toughness. The sample austempered at 400°C also showed poor properties due to the presence of initial martensite and coarse microstructure. The best combination of mechanical properties was achieved for the samples austempered at 325-350°C with a lower amount of retained austenite but with the highest mechanical stability.

show abstract

Section: Microstructurementioning

confidence: 99%

Mechanical Properties of a Bainitic Steel Producible by Hot Rolling

Rana

Chen

Haldar

et al. 2017

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

show abstract

“…Silicon and aluminium additions can achieve this by affecting the chemical driving force for the precipitation of cementite from austenite [5]. Many commercially successful steel concepts have been developed based on such mixed microstructures of bainitic ferrite and carbon-enriched retained austenite, reviewed in [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Thermal stability of austenite retained in bainitic steels

Podder

Bhadeshia

2010

Materials Science and Engineering: A

159

View full text Add to dashboard Cite

Steels with a microstructure consisting of a mixture of bainitic ferrite and carbon-enriched retained austenite are of interest in a variety of commercial applications because they have been shown to exhibit good combinations of strength, toughness and ductility. However, their use at temperatures moderately above ambient requires a knowledge of the thermal stability of the austenite. The changes that occur during the tempering of a mixture of bainitic ferrite, carbon-enriched retained austenite and martensite have been characterised. An analysis of the volume change due to transformation shows that it is possible to distinguish the decomposition of austenite from the tempering of martensite. The nature of the carbides that form during the heat treatment is discussed as are the implications on the development of mathematical models accounting for calculating the strain during austenite decomposition and martensite tempering. It is found that the early stages of tempering reactions where the austenite content is not greatly reduced, can dramatically influence the stability of the austenite as it is cooled to ambient temperature.

show abstract

“…H.K.D.H. Bhadeshia and Caballero F G [10][11] asserted that thinning bainite ferrite (BF) plates can further improve the properties of steel. Subsequently, J. Chakraborty [12][13] obtained ultrafine bainite and martensite by prior deformation and thermomechanical processing before the austenitization or austempering of SAE 52100 steel.…”

Section: Introductionmentioning

confidence: 99%

Effects of Spheroidized Microstructure on Bainite Nucleation in SAE 52100 Steel

Yang¹,

Yao²,

Yang³

et al. 2017

Proceedings of the 2017 5th International Conference on Mechatronics, Materials, Chemistry and Computer Engineering (ICMMCCE 20

View full text Add to dashboard Cite

Annealed SAE 52100 steel samples with different spheroidized microstructures were austempered to produce a bainitic+martensitic duplex microstructure. The effects of the spheroidized microstructure on bainite ferrite (BF) nucleation during austempering were discussed. Results show that the proportion of lower bainite increased, and the BF plates initially widened and subsequently narrowed in the duplex microstructure with an increase in the unit volume density of the cementite particles (ρ v ) in the spheroidized microstructure. An improved model was suggested to predict the bainite transformation including consummated α b by considering the effects of ρ v on BF nucleation. The model was validated with the experimental data of SAE 52100 steel.

show abstract

High Performance Bainitic Steels

Cited by 109 publications

References 28 publications

Mechanical Properties of a Bainitic Steel Producible by Hot Rolling

Mechanical Properties of a Bainitic Steel Producible by Hot Rolling

Thermal stability of austenite retained in bainitic steels

Effects of Spheroidized Microstructure on Bainite Nucleation in SAE 52100 Steel

Contact Info

Product

Resources

About