Acta Metallurgica Sinica (English Letters) ›› 1998, Vol. 11 ›› Issue (3): 215-224.

• Research paper • Previous Articles     Next Articles

THEORETICAL PREDICTION OF THE KINETICS CURVES OF PEARLITIC TRANSFORMATION IN HYPO-PROEUTECTOID STRUCTURAL STEELS

Z.G. Li; H.B. Chang; T. Y. Hsu ;Z. Y. Xu; and X. Y. Ruan (Department of Plasticity of Technology, Shanghai Jiao Tong University, Shanghai 200030, China)(Department of Metallurgical Engineering, Shanghai Technical College of Metallurgy, Shanghai 200233,China)(Department of Materials Science, Shanghai Jiao Tong University, Shanghai 200030, China)   

  • Received:1998-06-25 Revised:1998-06-25 Online:1998-06-25 Published:2009-10-10

Abstract: Supposing carbon contents of ferrite phases in pearlite precipitating from austenite in multicomponent steel at temperature T and in Fe-C ystem at T' are the same the pearlite formation temperature diference, can be calculated from the FeX phase diagrams and the equilibrium temperature Al. Using Tp and Fe-C binary thermodynamic model, the driving forces for phase transformation from austenite to pearlite in multicomponent steels have been successfully calculated. Through the combination of simplified Zener and Hillert's model for pearlite growth with Johnson-Mehl equation, using data from known TTT diagrams, the interfacial energy parameter and activation energy for pearlite formation can be determined and expressed as functions of chemical composition in steels by regression analysis. The calculated starting curves of pearlitic transformation in some commercial steels agree well with the experimental data.

Key words: pearlite formation temperature difference, interfacial energy parameter activation enerpy for pearlite transformation, Johnson-Mehl equation