A computational model for the prediction of steel hardenability

Abstract

A computational model is presented in this article for the prediction of microstructural development during heat treating of steels and resultant room-temperature hardness. This model was applied in this study to predict the hardness distribution in end-quench bars (Jominy hardness) of heat treatable steels. It consists of a thermodynamics model for the computation of equilibria in multicomponent Fe-C-M systems, a finite element model to simulate the heat transfer induced by end quenching of Jominy bars, and a reaction kinetics model for austenite decomposition. The overall methodology used in this study was similar to the one in the original work of Kirkaldy. Significant efforts were made to reconstitute the reaction kinetics model for austenite decomposition in order to better correlate the phase transformation theory with empiricism and to allow correct phase transformation predictions under continuous cooling conditions. The present model also expanded the applicable chemical composition range. The predictions given by the present model were found to be in good agreement with experimental measurements and showed considerable improvement over the original model developed by Kirkaldy et al.

Estudo Numérico e Experimental da Evolução Microestrutural e das Propriedades de Juntas Soldadas de Vergalhões pelo Processo GMAW

“…Os resultados de distribuição de temperatura obtidos por meio do modelo foram adicionalmente utilizados para previsão de tamanho de grão final da junta soldada utilizando um modelo cinético de crescimento de grão, descrito pela Equação 4 [14].…”

The Influence of Austenite Grain Size during Welding Simulations of Ferritic Steels

“…These models use the semi-empirical equations generated by Li et al [10] to capture the isothermal transformation kinetics in ferritic steels. In these equations, the austenite decomposition to ferrite, pearlite and/or bainite is determined as a function of both the chemical composition of the steel and the austenite grain size (G):…”

Effects of Chemical Composition and Austenite Deformation on the Onset of Ferrite Formation for Arbitrary Cooling Paths

“…Several phase transformation models that can be used for simulations along arbitrary cooling paths have been introduced earlier, for example, references [1][2][3][4][5][6][7][8][9][10][11]. However, there is currently no method that includes the effect of austenite deformation on the transformation start for different steel compositions and which could be used to calculate the transformation start for arbitrary cooling path.…”