The influence of the heating rate of cemented constructional steels on the growth of austenitic grain in the process of high-temperature holding
https://doi.org/10.29235/1561-8358-2018-63-4-399-406
Abstract
The influence of the heating mode of samples of constructional cemented steels 20ХН3А, 20ХГНР and 15ХГН2ТА on the value of austenite grain after high-temperature isothermal aging at 1000 °С is studied. It is shown that the heating of steels at a rate of 1.2–3.0 °C / min in the phase-transformation interval stabilizes the grain structure of the steels and leads to a slowing down of the kinetics of the growth of austenite grains during prolonged high-temperature aging, which makes it possible to increase the temperature of the chemical-thermal treatment of steels. It is concluded that the stabilization of the grain structure of steels is associated with the formation of segregation of impurity atoms and particles at grain boundaries with high-angle disorientation during slow heating, which prevents migration of grain boundaries in the process of prolonged high-temperature aging. A high-temperature chemical-thermal treatment of a batch of billets from steel 20ХН3А under experimental conditions with stepwise heating in the phase-transformation interval provided a qualitative fine-grained structure of the cemented layer.
About the Authors
V. A. Kukareko
Joint Institute of Mechanical Engineering of the National Academy of Sciences of Belarus, Minsk
Belarus
D. Sc. (Physics and Mathematics), Professor, Head of the Center for Structural Research and Tribo-Mechanical Testing of Materials and Engineering Products
Belarus
D. Sc. (Physics and Mathematics), Professor, Head of the Center for Structural Research and Tribo-Mechanical Testing of Materials and Engineering Products
A. L. Valko
Joint Institute of Mechanical Engineering of the National Academy of Sciences of Belarus, Minsk
Belarus
Senior Researcher
Belarus
Senior Researcher
A. N. Chichin
Minsk Tractor Works, Minsk
Belarus
Engineer-technologist of II category
Belarus
Engineer-technologist of II category
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