1. | Rolling of steel at 1100° and higher leads to austenite grain growth after annealing. |
2. | A recrystallization threshold appears with plastic deformation at temperatures up to 1100°, the range of the recrystallization threshold broadening as the temperature of the preceding plastic deformation decreases. Plastic deformation =20% at 1150° always leads to a jump of austenite grain growth with repeated quenching, and for steel rolled at 1150 and 1200° the region of austenite grain growth broadens to =30–40%. |
3. | At all degrees of deformation at different temperatures the average diameter of austenite grains decreases with decreasing preliminary rolling temperatures and increasing degrees of repeated plastic deformation. This undoubtedly affects the consistency of the properties inherited by high-speed steel during subsequent high-temperature plastic deformation. |