Prediction of dendrite arm spacing for low alloy steel casting processes

Abstract

Simple mathematical expressions to predict the primary dendrite arm spacing (PDAS) and secondary dendrite arm spacing (SDAS) suitable for steel casting processes are presented. The equations of the PDAS and SDAS were based on previously published experimental data for low alloy steels. Good agreement was obtained between previous measurements of dendrite arm spacing (DAS) and the model predications in the range of cooling rate occurring in steel casting processes. The results indicated that the cooling rate and carbon content basically govern the calculation of PDAS, especially for low carbon steel. However, the carbon content governs the selection of mathematical expression to predict SDAS for low alloy steels. Dendritic growth is the most common crystallization mechanism in industrial steels. Many empirical expressions have been employed to correlate the PDAS and SDAS with growth rate, temperature gradient, cooling rate, and local solidification time. However, the comparative advantages of the various expressions with respect to the accuracy with different types of steels remain unclear. Thus, the aim of the present study is to develop simple expressions to predict DAS as a function of carbon content and thermal conditions of low alloy steels.