Evolution of Austenite Grain Structure and Microalloying Element Precipitation During Heating of Steel of Strength Class K65 (X80) for Rolling

Abstract

The effect of temperature and soaking time during slab heating for rolling on austenite structure size and uniformity, and dissolution of microalloying element precipitates, is considered. It is shown that the heating regime has a strong effect on austenite structure uniformity. With an increase in heating temperature, there is anomalous growth of individual grains, and this is a consequence of gradual microalloying element dissolution. As a result of this, boundaries acquire mobility, thus leading to generation of secondary recrystallization and significant inhomogeneity, and embrittlement of the structure. It is also shown that austenite grain size and distribution after heating is inherited during roughing rolling.