Die steels with high heat resistance and toughness

1. Steels for pressing high-strength alloys must contain M6C carbide in order to retain a high yield strength (80–120 kgf/mm2) at temperatures up to 650–720°. 2. The heat resistance is highest (730–740°) and the notch toughness lowest (an=0.8–1.5 kgf-m/cm2) for the steel with ∼8–9% W. 3. Steels of the first group (2Kh6V8M2K8 type) are intended for pressing without substantial dynamic loads and intensive cooling. They should be quenched from 1190–1210° and tempered at 700–710° (HRC 50-51) or 745–750° (HRC 45-46). Steels of the second group (2Kh5V5M2K5 type) are used for pressing with dynamic loads and intensive cooling. They are quenched from 1190–1230° and tempered at 620–625° (HRC 50-51) or at 680–685° (HRC 45-46).