An approach to calculating the casting temperature of high-manganese austenite steel

This study is devoted to influence of the temperature procedures of high-manganese austenite steel casting on formation of the internal structure and properties of castings. An example of a high-manganese austenite steel Fe-1.1C-16Mn-0.8Si-1.3Cr-Mo-Ni is considered, which differs from the generally accepted composition of Hadfield steel (110G13L) by an expanded Mn content and combined alloying with carbide-forming elements. The study applied an approach to choosing the optimal casting temperature, which is implemented using pre-computer modeling of the cast structure by the Cellular Automaton Finite Element method, followed by verification on physical samples. An analysis of the microstructure of the experimental samples obtained at the selected casting temperatures indicates the accuracy of conducted calculation: the discrepancy between grain sizes does not exceed 5 mu m (4.4 %). Rational temperature contributes to formation of more fine microstructure and, accordingly, a high level of mechanical properties: pouring the alloy under study at 1390-1410 degrees C makes it possible to obtain an average grain size of 113-116 mu m, minimal mass loss upon contact with the abrasive (1.74-1.81 %) and increased impact strength (28.5-28.3 kgf center dot m/cm2). Subsequent approximation of the calculated values and obtaining a regression equation using the Reduced Major Axis method allows in practice to predict reliably (with determination coefficient 0.826) the grain size of the casting at the selected casting temperature without using additional software.