Formation conditions of coarse columnar austenite grain structure in peritectic carbon steels by the discontinuous grain growth mechanism

The discontinuous grain growth leading to a coarse columnar austenite grain (CCG) structure in as-cast peritectic carbon steels is analyzed by means of two- and three-dimensional phase-field simulations. On the basis of theory of grain growth, the conditions for discontinuous grain growth to occur is elucidated in terms of cooling condition and material properties. The theoretical analysis well explains the results of the phase-field simulations and it should be useful in predicting the formation of the CCG structure in continuously-cast slabs.