Temper brittleness temperature of H13 and LD steel?

New high strength and toughness cold working die steel 7Cr7Mo3V2Si (code SRIM LD) 7Cr7Mo3V2Si (code SRIM LD) Cold working die steel has high strength, good toughness, wear resistance, cold, hot working process performance is excellent, quenching temperature range is wide, heat treatment deformation is small and so on. Its bending strength than Cr12MoV steel nearly double, toughness is 2 to 3 times higher, is currently the ideal cold working die materials, was awarded the Ministry of Machinery 3 major scientific and technological achievements. Cold heading die quenching 1, using low temperature quenching high toughness, 1100 ℃ quenching, 530 ~ 550 ℃ tempering 2, high strength, comprehensive mechanical properties, 1150 ℃ quenching, 550 ℃ three times tempering (forging and stamping 2005-7) 2, quenching 1, 550 ℃ preheating, 800 ℃ preheating, 1090 ~ 1100 pre-cooling quenching oil, 520 ~ 540 ℃ tempered twice, 58 ~ 60HRC 3, cold heading die material, cold heading die material is the ideal cold working material. 60HRC three, cold heading standard parts cutting edge die heat treatment (metal heat treatment 2001-5) 1, 1080 ℃ heating quenching oil, 300 ~ 400 ℃ out of the oil air-cooled, 61.5 ~ 62.5HRC 2, 350 ~ 450 ℃ × 1h nitrate in the medium-temperature tempering, 540 ℃ × 1h, 2 ~ 3 times tempering four, complex shaped powder metallurgy mold heat treatment (metal heat treatment) (2001-5) 1, 1120 ℃ quenching + 630 ℃ tempering 3 times hardness 50 ~ 52HRC, quenched at 1120 ℃, austenite grain fine, uniform, after high temperature tempering, steel hardness decreases, toughness increased significantly. This process is suitable for molds working under high impact load. 2、 Quenched at 1120℃+tempered at 610℃ for 3 times. Hardness is 56~58HRC, the tempering temperature is reduced appropriately, which improves the hardness and strength of the steel. This process is suitable for molds working under higher pressure and bearing certain impact load. 3、 Quenched at 1120℃ + tempered at 590℃ for 3 times. Hardness 59~61HRC, reduce the tempering temperature appropriately, improve the hardness, strength and wear resistance of steel. This process is suitable for molds with small impact loads that require high resistance