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The diffusional transformation of pearlite to austenite takes place when the iron alloy with a matrix containing pearlite is heated to a temperature above Ac1. Development of the transformation contains two stages. The first stage is the formation of austenite nuclei. The second stage involves the growth of the austenite nuclei up to the moment of a complete transformation of the pearlite into austenite. The transformation rate depends on the parameters of the initial microstructure and also on the temperature transformation. Among parameters of the initial structural the most important are: the thickness of a cementite and a ferrite plate (called interlamellar distance) and the size of the pearlite colony. Following the Roosz at al. [1] at a numerical model of the pearlite-austenite transformation has been developed. It allows for the calculation of the time of the transformation at an assumed temperature as well as to determine the TTT diagram for the assigned temperature range. The developed computer program also enables to calculate the CHT diagram. The results of modeling the transformation showed a strong influence of the size of pearlite colony and interlamellar distance on the transformation kinetics. Decrease of the interlamellar distance reduces the time needed to end of the transformation. Verification of the derived model using published data was done.
Keywords: Pearlite, TTT diagrams, CHT diagrams, modelling of phase transformations© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.