Modelling the Static Recrystallization Kinetics of Microalloyed TWIP Steels with Different Alloying Contents

During hot rolling, austenite recrystallization determines the grain size evolution and the extent of strain accumulation, and therefore, it can be used to tailor the microstructure and mechanical properties of the final product. However, at the moment, models describing the recrystallization kinetics of high-Mn steels are scarce and they do not take into account the effect of the alloying elements present in these steels. The aim of this work is to provide a quantitative model for the determination of the static recrystallization kinetics valid for a wide range of high-Mn steel compositions. Softening data determined for steels with different Mn (20 to 30%), Al (0 to 1.5%) and C (0.2 to 1%) levels at different strain, strain-rate and temperature conditions were analyzed. Static recrystallization of the investigated high-Mn steels follow Avrami’s law, with n Avrami exponents which are temperature dependent and lower than those determined for low C steels. A dependence of the t0.5 (time for 50% fractional softening) on the carbon content has been also observed and it was incorporated into an equation for the calculation of this parameter.

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Characteristics of the Static Recrystallization Kinetics of an Intercritically Deformed C-Mn Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.467-470.293 ◽

2004 ◽

Vol 467-470 ◽

pp. 293-298 ◽

Cited By ~ 2

Author(s):

Haiwen Luo ◽

Jilt Sietsma ◽

Sybrand van der Zwaag

Keyword(s):

Stress Relaxation ◽

Static Recrystallization ◽

Avrami Exponent ◽

Recrystallization Kinetics ◽

Ferrite Fraction ◽

Austenite Recrystallization ◽

Austenite Grains ◽

Intercritical Region ◽

Mn Steel ◽

Kinetics Of

The austenite recrystallization kinetics in the intercritical region of a C-Mn steel is investigated by means of stress relaxation tests. It is found that the Avrami exponent, n, decreases significantly with decreasing temperature, i.e. with increasing ferrite fraction. This behaviour deviates from that of austenite recrystallization in the purely austenitic state, in which case the Avrami exponent is constant and independent of temperature and deformation. To interpret this, the influence of spatial variation of the plastic strain in the intercritical austenite grains on recrystallization kinetics is modelled quantitatively. The modelling results seem to indicate that the strain heterogeneity is responsible for the decreasing Avrami exponent with decreasing intercritical temperature.

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Research on Austenite Static Recrystallization Kinetics of Ultra-High Strength Dual Phase Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.631-632.310 ◽

2013 ◽

Vol 631-632 ◽

pp. 310-313

Author(s):

Zhuang Li ◽

Di Wu ◽

Wei Lv ◽

Zhen Zheng ◽

Shao Pu Kang

Keyword(s):

Dual Phase Steel ◽

Static Recrystallization ◽

High Strength ◽

Recrystallization Temperature ◽

Dual Phase ◽

Recrystallization Kinetics ◽

Softening Curve ◽

Austenite Recrystallization ◽

Deformation Test ◽

Kinetics Of

In this paper, double deformation test was conducted in a MMS-300 thermomechanical simulator. Austenite static recrystallization kinetics of ultra-high strength dual phase steel was investigated. The results have shown that the softening fractions increase with holding time as a whole. Under deformation temperatures of 950°C, 1000°C and 1050°C, the softening fractions increase with the increase of the deformation temperature. And the softening curve appears relatively flat under deformation temperatures of 950°C. The austenite no-recrystallization temperature (Tnr) of ultra-high strength dual phase steel was between 900°C and 950°C. Double deformation test conditions which promoted Nb(CN) precipitation resulted in a decrease of a austenite recrystallization. Strain induced precipitation of Nb (CN) was the main reason why the softening curve appeared a plateau.

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Kinetics of Austenite Recrystallization of Selected Steels Used for Heavy Forgings

Materials Science Forum ◽

10.4028/www.scientific.net/msf.782.93 ◽

2014 ◽

Vol 782 ◽

pp. 93-98

Author(s):

Jakub Horník ◽

Petr Zuna ◽

Jaroslav Malek ◽

František Jandoš

Keyword(s):

Grain Growth ◽

Static Recrystallization ◽

Chemical Elements ◽

Grain Coarsening ◽

Recrystallization Kinetics ◽

Austenite Recrystallization ◽

One Step ◽

Kinetics Of

The kinetics of austenite recrystallization was evaluated in range of typical forging temperatures (850 - 1250) °C. The steels SA-508 and 3.5Ni-1.5Cr were compared. The laboratory one step deformation was applied. The effect of selected chemical elements in evaluated steels on grain growth and recrystallization kinetics of austenite and precipitation was monitored using metallographic methods. The retarding of static recrystallization was proved and no abnormal grain coarsening at defined condition was observed.

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