Effect of austenite microstructure and cooling rate on transformation characteristics in a low carbon Nb–V microalloyed steel

Olasolo, Maider; Uranga, Pello; Rodríguez-Ibabe, J.M.; López, Beatriz

doi:10.1016/j.msea.2010.11.078

Cited by 142 publications

(54 citation statements)

References 36 publications

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“…[48,49] The main phase components in all transformed microstructures in this research, AF and BF, both are displacive transformation products and, thus, have similar transformation shape strains. [4] Given that, the boundary densities in range 1 should be close.…”

Section: Effect Of Austenite Deformation On Boundary Densitiesmentioning

confidence: 82%

Effect of Austenite Deformation on the Microstructure Evolution and Grain Refinement Under Accelerated Cooling Conditions

Zhao

Palmiere

2017

Metall and Mat Trans A

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Although there has been much research regarding the effect of austenite deformation on accelerated cooled microstructures in microalloyed steels, there is still a lack of accurate data on boundary densities and effective grain sizes. Previous results observed from optical micrographs are not accurate enough, because, for displacive transformation products, a substantial part of the boundaries have disorientation angles below 15 deg. Therefore, in this research, a niobium microalloyed steel was used and electron backscattering diffraction mappings were performed on all of the transformed microstructures to obtain accurate results on boundary densities and grain refinement. It was found that with strain rising from 0 to 0.5, a transition from bainitic ferrite to acicular ferrite occurs and the effective grain size reduces from 5.7 to 3.1 lm. When further increasing strain from 0.5 to 0.7, dynamic recrystallization was triggered and postdynamic softening occurred during the accelerated cooling, leading to an inhomogeneous and coarse transformed microstructure. In the entire strain range, the density changes of boundaries with different disorientation angles are distinct, due to different boundary formation mechanisms. Finally, the controversial influence of austenite deformation on effective grain size of low-temperature transformation products was argued to be related to the differences in transformation conditions and final microstructures.

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Section: Effect Of Austenite Deformation On Boundary Densitiesmentioning

confidence: 82%

Effect of Austenite Deformation on the Microstructure Evolution and Grain Refinement Under Accelerated Cooling Conditions

Zhao

Palmiere

2017

Metall and Mat Trans A

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“…It is generally accepted that the grain boundary migration velocity (v) is proportional to the driving force (Seok et al, 2014;Maalekian et al, 2012;Yue et al, 2010;Olasolo et al, 2011;Alogab et al, 2007;Hodgson and Gibbs, 1992;Nanba et al, 1992), an approximation justified at the relatively small driving forces involved in grain growth. This velocity is given by the expression (Stumpf, 2010) [1]…”

Section: Development Of a Constitutive Equationmentioning

confidence: 99%

“…It is also known that the austenite grain size directly influences the microstructure, and thus the mechanical properties, of the steel (Maalekian et al, 2012;Yue et al, 2010). Effective grain growth control is reported to be achieved through addition of precipitate-forming elements, such as Nb that, slow down the grain boundary migration through pinning and solute drag mechanisms (Yu et al, 2010;Olasolo et al, 2011;Alogab et al, 2007). Much work has been carried out on austenite grain lsize control by the addition of precipitate-forming elements that have a strong affinity for interstitial elements, such as carbon and nitrogen, which form the dispersed pinning particles to inhibit the austenite grain growth (Alogab et al 2007;Hodgson and Gibbs, 1992;Nanba et al, 2003;Flores and Martinez, 1997;Rollett, Srolovitz and Anderson, 1989).…”

Section: Introductionmentioning

confidence: 99%

The influence of niobium content on austenite grain growth in microalloyed steels

Annan

Siyasiya

Stumpf

2015

J. S. Afr. Inst. Min. Metall.

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“…For this purpose, the experimental data of five low-carbon microalloyed steels with different chemical compositions have been used [30][31][32][33][34] . The chemical compositions of these steels are summarized in Table 1.…”

Section: Data Collectionmentioning

confidence: 99%

Application of ANFIS for modeling of microhardness of high strength low alloy (HSLA) steels in continuous cooling

Khalaj

Nazari²,

Livary³

2013

Mat. Res.

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The paper presents some results of the research connected with the development of new approach based on the Adaptive Network-based Fuzzy Inference Systems (ANFIS) of predicting the Vickers microhardness of the phase constituents occurring in five steel samples after continuous cooling. The independent variables in the model are chemical compositions, initial austenite grain size and cooling rate over the temperature range of the occurrence of phase transformations. To construct these models, 114 different experimental data were gathered from the literature. The data used in the ANFIS model is arranged in a format of twelve input parameters that cover the chemical compositions, initial austenite grain size and cooling rate, and output parameter which is Vickers microhardness. In this model, the training and testing results in the ANFIS systems have shown strong potential for prediction of effects of chemical compositions and heat treatments on hardness of microalloyed steels.

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Effect of austenite microstructure and cooling rate on transformation characteristics in a low carbon Nb–V microalloyed steel

Cited by 142 publications

References 36 publications

Effect of Austenite Deformation on the Microstructure Evolution and Grain Refinement Under Accelerated Cooling Conditions

Effect of Austenite Deformation on the Microstructure Evolution and Grain Refinement Under Accelerated Cooling Conditions

The influence of niobium content on austenite grain growth in microalloyed steels

Application of ANFIS for modeling of microhardness of high strength low alloy (HSLA) steels in continuous cooling

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