For a better understanding of new steel 33Mn2V for oil-well tubes,
austenite grain growth behavior of the steel is experimentally studied at various elevated temperatures and holding for different times. Although the steel has no sharp defined grain
coarsening temperature from the grain size-temperature curve, a kind of
Austenite grain coarsening temperature is practically defined as about 1250 ℃ according to ASTM grain size grade G=5.00. It is also found that, when heating within the range from 900 ℃ to 1250℃, the temperature dependence of the average austenite grain size (μm) of the steel can be well described by an Arrhenius-type equation: D = 1.12×104exp(-8.31×103/T). Isothermal growth equations of austenite grains in parabolic type with the exponent close to 1/2 are also obtained when the steel was heated at 1100℃ and 1200 ℃, respectively. The results show that the steel has good anti-coarsening ability at elevated temperatures, which is very important in putting the said steel into industrial production of N80 grade hot-rolling non-quenched/tempered seamless oil-well tubes.