Details

Title

Mathematical Model of Bainitic Transformation in Austempered Ductile Iron

Journal title

Archives of Foundry Engineering

Yearbook

2017

Numer

No 4

Publication authors

Keywords

Industrial and Manufacturing Engineering ; Metals and Alloys

Divisions of PAS

Nauki Techniczne

Abstract

<jats:title>Abstract</jats:title><jats:p>A mathematical model of austenite - bainite transformation in austempered ductile cast iron has been presented. The model is based on a model developed by Bhadeshia [1, 2] for modelling the bainitic transformation in high-silicon steels with inhibited carbide precipitation. A computer program has been developed that calculates the incubation time, the transformation time at a preset temperature, the TTT diagram and carbon content in unreacted austenite as a function of temperature. Additionally, the program has been provided with a module calculating the free energy of austenite and ferrite as well as the maximum driving force of transformation. Model validation was based on the experimental research and literature data. Experimental studies included the determination of austenite grain size, plotting the TTT diagram and analysis of the effect of heat treatment parameters on the microstructure of ductile iron. The obtained results show a relatively good compatibility between the theoretical calculations and experimental studies. Using the developed program it was possible to examine the effect of austenite grain size on the rate of transformation.</jats:p>

Publisher

The Katowice Branch of the Polish Academy of Sciences

Date

2017

Identifier

ISSN 2299-2944

DOI

10.1515/afe-2017-0158

×