P20, American AISI standard pre-hardened plastic mold steel, good machining performance, excellent polishing performance, a certain toughness, can be carburized, surface hardness is up to 65HRC after carburizing quenching, with higher hot hardness and wear resistance. 2. Supply Condition: Pre-hardened, Hardness 30~35HRC. 3. Transformation temperature(Approx): AC1=770° C, AC3=825° C, Ar1=640° C, Ar3=760° C, Ms=300° C, Mf=120° C 4. Thermal processing specification: Heating temperature 1100~1150° C, Beginning forging temperature 1050~1100° C, Ending forging temperature ≥ 850° C, then air cooling. 5. Annealing specification: Heating temperature 1100~1150° C, holding time 2 ~ 4 h, the isothermal temperature 720° C, holding time 4 ~ 6h, furnace cooling to 500° C, released, then air cooling. 6. Quenching and Tempering specification: Quenching temperature 860~870° C, oil quenching, Tempering temperature 540~580° C, hardness 30~35HRC.