Mathematical modeling of austenite transformation kinetics during cooling of lowcarbon steel considering the effect of strain

Authors

  • A. I. Trotsan Dr. Sc. (Tech.), Prof, Ukraine
  • V. V. Kaverinsky Ph.D., Ukraine
  • G. A Baglyuk Dr. Sc. (Tech.), Prof, Ukraine
  • Z. P. Sukhenko

Keywords:

mathematical modeling, phase transformations, austenite steel, deformation

Abstract

Annotation. Purpose. A study of high-temperature deformation of low-carbon steel impact on the kinetics of austenite transformations and a structure formation at different cooling rates using computer simulation. Methods. The main research tool is a physically based computer model describing the kinetics of austenite transformation in steel during cooling. As research material selected low-carbon steel 15. Findings. Here was modeled a process, describing the transformation kinetics of austenite in arbitrary composition steels, allowing also qualitatively and quantitatively predict the metal structure formation. Using as an example a lowcarbon low-alloyed steel the feasibility of the model to predict the impact of pre-high-temperature deformation on the steel structure during the phase transformation was demonstrated. It was shown an increasing of ferrite transformation rate in the deformed steel which causes ferrite grain refinement and prevent a formation of low-carbon martensite in the final structure. Originality. Using a computer model quality and quantity effects austenite of pre-strain at 930 °C in the steel 15 were studied. It is found that predeformation with a degree of 50% can in the 1.5 - 2.0 (depending on the cooling rate) times refines ferrite grain size and prevents the formation of low-carbon martensite. The degree of pre-deformation effect on the kinetics of austenite transformation decreases with a decrease in the cooling rate. Practical value. Computer simulation of supercooled austenite transformation processes allows you to quickly and cost-effectively get the information necessary for thermal and thermo-mechanical processing technologies development and improvement. In particular it is shown that when the formation of martensite and bainite structures in the conditions of accelerated cooling is not desirable, preliminary deformation of a low carbon low alloyed steel at a temperature slightly higher than A3 can significantly reduce their quantity while significantly (up to 1.5 – 2.0 times) ferrite grains refinement.

Author Biographies

A. I. Trotsan, Dr. Sc. (Tech.), Prof

отдел износостойких и коррозионностойких порошковых конструкционных материалов, Институт проблем материаловедения НАН Украины, ул. Кржижановского, 3, 03680, Киев, Украина

V. V. Kaverinsky, Ph.D.

 

G. A Baglyuk, Dr. Sc. (Tech.), Prof

отдел износостойких и коррозионностойких порошковых конструкционных материалов, Институт проблем материаловедения НАН Украины, ул. Кржижановского, 3, 03680, Киев, Украина

Z. P. Sukhenko

отдел износостойких и коррозионностойких порошковых конструкционных материалов, Институт проблем материаловедения НАН Украины, ул. Кржижановского, 3, 03680, Киев, Украина

References

Golod V. M. Vychislitel'naja termodinamika v materialovedenii [Computational Thermodynamics in Materials Engineering] / V. M. Golod, K. D. Savel'ev. – St. Petersburg: Publishing of the Polytechnic University, 2010. – 217 p. (in Russian)

Golikov P. A. Raschjot kojefficienta diffuzii ugleroda v staljah i ego prilozhenie v modelirovanii fazovyh prevrashhenij i nauglerozhivanija [Calculation of carbon diffusion coefficient in steel and its application in modeling of phase transformations and carburizing]: Dis. cand. tehn. Science / P. A. Golikov. – St. Petersburg, 2011. - 176 p. (in Russian)

Komp'juternoe modelirovanie fazovyh prevrashhenij v kompleksno legirovannoj stali [Computer modeling of phase transformations in the complex alloy steel] / A. I. Trocan, V. V. Kaverinsky, I. L. Brodecky, Z. P. Suhenko // Stroitel'stvo, materialovedenie, mashinostroenie: Starodubovskie chtenija 2016. [Construction, materials science, mechanical engineering: Starodubov reading in 2016.] – Dnepropetrovsk: PGSA, 2016. - Vol. 89. – pp. 177 – 181. (in Russian)

Kaverinsky V. V. Computer program for modeling of phase transformations. – Certificate of copyright registration number 70573 from 02.22.2017.

Modelirovanie γ ® α-prevrashhenija v staljah [Modeling of γ®α-transformations in steels] A. A. Vasil'ev, D. F. Sokolov, N. G. Kolbasnikov, S. F. Sokolov // Fizika tvjordogo tela [Solid State Physics]. – 2012. – V. 54. – Vol. 8. – pp. 1565 – 1574. (in Russian)

Modelirovanie vlijanija sostava trubnyh stalej i rezhima termicheskoj obrabotki na kinetiku raspada austenita i strukturu ferrita [Modeling of the effect of pipe steels composition and heat treatment conditions on the kinetics of austenite decay and ferrite structure] / N. Ju. Zolotorevskij, E. V. Nesterova, E. I. Hlusova et. all. // Voprosy materialovedenija [Materials Questions]. – 2011. - № 3. – pp. 38 – 52. (in Russian)

Bhadeshia H.K.D.H. Bainite in steels / H.K.D.H. Bhadeshia // The Institute of Materials: London, UK. – 1992. – 468 p.

Influence of deformation on austenite to ferrite transformation in low carbon steels: experimental approach and modeling [Text] / S. Lacroix, Y. T. Breche, M. Veron e. a. // Austenite Formation and Decomposition. – Warrendale, PA, 2003. – P. 367 – 379.

Vasilyev A. Carbon diffusion coefficient in complexly alloyed austenite [Text] / A. Vasilyev // Detroit: Proc. MS&T, 2007. – P. 537 – 551.

Yoshie A. Formation of flow stress on Nb added steels by considering work-hardening and dynamic recovery [Text] / A. Yoshie // ISIJ Int. – 1996. – V. 36. – P. 467 – 473.

Published

2017-03-28

Issue

Section

Proceedings in memory of Starodubov