Computer simulation of phase transformations in a complex alloyed steel

Authors

  • A. I. Trotsan Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine, Ukraine
  • V. V. Kaverinsky Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine, Ukraine
  • I. L. Brodetsky Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine, Ukraine
  • Z. P. Sukhenko Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine, Ukraine

Keywords:

phase transitions, thermodynamics, austenite, pearlite, steel alloying, computer model.

Abstract

Purpose.  Development  and  implementation  of  a  computer  model  to  analyze  the  effects  of  steel  chemical composition of at the equilibrium temperature of the beginning and end of the   α transformation, the position of the solvus lines of ferrite and austenite, as well as the temperature and carbon concentration corresponding to the eutectoid (pearlite). Methodology.Thermodynamic modelling based on conditions of the chemical potentials equality of α,  and  (cementite) phases determination. When determining the shape of the curves for the potential (geometric representation of Gibbs energy concentration dependence) ofeach  phase used approach of Sundman-Ågren sublattice  model with Redlich-Kister  polynomial  to  calculate  the  excess  energy  of mixing. To determine the equations of common tangents to the curves of potentials used methods for numerical differentiation in combination with the method of least squares in order to find equal values of the slope and intercept. To implement calculations used written in C ++ module, which is a part of a software project for the simulation of phase transformations. Results. The computer model allows determining the phase transformation temperature of the steel and the equilibrium content of the carbon in phases at a predetermined temperature. Examples of the effect of Mn, Si, Ni, Cr and Mo on the shape of a quasi-binary polythermal section ofphase Fe-C  with  alloying  elements diagrams near eutectoid (pearlite) transformation calculations are  given. Originality. Using physically grounded modelling method a quantitative relationship between the composition of complex alloyed steel and the position of its critical points was shown. Practical value. Was build a computer model which using previously developed software, enables a high  degree  of  reliability  calculation  of carbonitride  phases formation  in  steels,  in  particular  the  conditions of excessive  phase precipitation process, as well as gives information for adjusting the temperature of an effective thermal and/or thermo-mechanicalprocessing for specified composition steel.

Author Biographies

A. I. Trotsan, Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine

Dr. Sc. (Tech.), Prof.

V. V. Kaverinsky, Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine

Ph.D. (Tech.), Researcher

I. L. Brodetsky, Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine

Ph.D. (Tech.), Senior Scientist

Z. P. Sukhenko, Department of Steel Materials, Institute for Problems of Materials Science, Krzyzanowsky st., 3, 03680, Kiev, Ukraine

Chief Constructor

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Published

2016-03-22

Issue

Section

Proceedings in memory of Starodubov