Prediction of post-dynamic austenite-to-ferrite transformation and reverse transformation in a low-carbon steel by cellular automaton modeling

Austenite–ferrite transformation at different isothermal temperatures in low carbon steel was investigated by a two-dimensional cellular automaton approach, which provides a simple solution for the difficult moving boundary problem that governs the ferrite grain growth. In this paper, a classical model for ferrite nucleation at austenite grain boundaries is adopted, and the kinetics of ferrite grain growth is numerically resolved by coupling carbon diffusion process in austenite and austenite–ferrite (γ–α) interface dynamics. The simulated morphology of ferrite grains shows that the γ–α interface is stable. In this cellular automaton model, the γ–α interface mobility and carbon diffusion rate at austenite grain boundaries are assumed to be higher than those in austenite grain interiors. This has influence on the morphology of ferrite grains. Finally, the modeled ferrite transformation kinetics at different isothermal temperatures is compared with the experiments in the literature and the grid size effects of simulated results are investigated by changing the cell length of cellular automaton model in a set of calculations.

Download Full-text

Numerical simulation of dynamic strain-induced austenite–ferrite transformation in a low carbon steel

Acta Materialia ◽

10.1016/j.actamat.2009.03.005 ◽

2009 ◽

Vol 57 (10) ◽

pp. 2956-2968 ◽

Cited By ~ 47

Author(s):

Chengwu Zheng ◽

Namin Xiao ◽

Luhan Hao ◽

Dianzhong Li ◽

Yiyi Li

Keyword(s):

Numerical Simulation ◽

Carbon Steel ◽

Low Carbon Steel ◽

Dynamic Strain ◽

Low Carbon ◽

Ferrite Transformation

Download Full-text

Effect of Starting Microstructures on the Reverse Transformation Kinetics in Low-Carbon Steel

Metals ◽

10.3390/met10121601 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1601

Author(s):

Junhua Hou ◽

Binbin He

Keyword(s):

Grain Size ◽

Carbon Steel ◽

Low Carbon Steel ◽

Reverse Transformation ◽

Transformation Rate ◽

Low Carbon ◽

Transformation Kinetics ◽

Forward Transformation ◽

Different Grain Size ◽

Initial Starting

The effect of the initial starting microstructures on the austenite reverse transformation kinetics is thoroughly studied in low-carbon steel. The different initial starting microstructures including the ferrite + pearlite, bainite, and martensite are obtained through varied forward transformation. It is found that the bainite phase demonstrates highest reverse transformation rate while the ferrite + pearlite shows the lowest transformation rate. The above observation can be explained through the different grain size of the initial starting microstructures as the grain boundaries could act as the nucleation sites for austenite reverse transformation. The explanation is further substantiated based on the consideration of the reverse transformation kinetics from the martensite microstructure with different grain size.

Download Full-text

Texture Developments during Ferrite Refinement through Deformation-Enhanced Ferrite Transformation and Dynamic Recrystallization in Low Carbon Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.165 ◽

2005 ◽

Vol 475-479 ◽

pp. 165-168 ◽

Cited By ~ 2

Author(s):

Ping Yang ◽

Wang Yue Yang ◽

Zu Qing Sun

Keyword(s):

Grain Size ◽

Carbon Steel ◽

Dynamic Recrystallization ◽

Recrystallization Texture ◽

Low Carbon Steel ◽

Deformation Texture ◽

Low Carbon ◽

Ferrite Transformation ◽

Transformation Texture ◽

Ferrite Grain Size

Texture evolutions are determined by XRD and EBSD techniques during ferrite refinement through deformation-enhanced ferrite transformation (DEFT) and dynamic recrystallization (DREX). Evidences of transformation texture, deformation texture and recrystallization texture during DEFT are provided and compared with the texture during DREX. The influence of pass-interval during DEFT on texture is illustrated. Results are discussed in terms of the influences of ferrite grain size and deforming temperature.

Download Full-text