Modeling Pearlite Transformation in Super-high Strength Wire Rods: I. Modeling and Simulation in Fe–C–X Ternary Alloys

Abstract

A computer model was developed to simulate pearlite transformation in Fe-C base near-eutectoid alloys during isothermal holding, continuous cooling and patenting in view of its application to high carbon super-high strength wire rods. The model is based upon Johnson-Mehl-Avrami theory; it consists of calculation of nucleation and growth rates and conversion of the extended to real volume as well as calculation of lamellar spacing from the well-known correlation with undercooling. Calculated pearlite start and finish temperatures, number and size of nodules and lamellar spacing were in good agreement with those obtained from Gleeble thermomechanical simulation.

Modeling Pearlite Transformation in Super-high Strength Wire Rods: II. Simulation in Fe–C Base Multi-component Alloys

“…1) In Figs. 12(a) and 12(b) are shown transformation curves and lamellar spacings calculated at a cooling rate of 6°C/s with and without recalescence.…”

“…The nucleation rate was calculated phenomenologically incorporating nucleation rate data in Fe-C alloy from the equation, .................. (1) where D C γ is the carbon diffusivity in austenite, 5) T is temperature, Teu is the eutectoid temperature and A and B are constants. The growth rate was calculated from the equation proposed by Tewari and Sharma for no-partitioned growth.…”

“…In a companion paper 1) pearlite transformation during patenting was modeled in Fe-C base alloys on the basis of Johnson-Mehl-Avrami theory. In this paper the model was applied to multicomponent high carbon near-eutectoid alloys, i.e., experimental super-high strength wire rods.…”