Case Heat-treating Techniques Of Pressure Cast Dies

Comparing H13 steel with traditional 3Cr2W8V,it has higher high-temperature endurance and resistant of heat fatigue besides relatively high powerful thermal trait and heat rigidity trait.Moreover,H13 is cheaper for its bigger conducting-heat coefficient,smaller linear expansion .coefficient ,lower quencher temperature and smaller density compared with 3Cr2W8V steel. The advantages of HI3 make it have bigger internal latent capability than 3Cr2W8Vduring making heat-operation mould steel. So,in this paper,H13 is used as study object,its quencher and temper technics are studied too. The result indicated that by using twice-salted classification quencher HI3 steel could get bigger impulsion endurable trait than once-salted classification quencher. Moreover,some surface procession technics experiments such as SNC common penetration and oxygenation procession ,RE-SNC common penetration procession and RE-SNC common penetration and oxygenation procession are separately carried out on H13 steel .The processed sample was separated carried out experiments of heat-fatigue trait .wearable trait and anti-oxygenation under high temperature. The result indicated that ,under the condition of air oxygenation,the heat-fatigue trait of penetrating layer adulterated RE was higher than that of unadulterated RE. In order to study the action that RE effected wearable trait and high temperature anti-oxygenation of HI 3 steel SNC common penetration and oxygenation complex procession ,experiment sample penetration layer complexly processed under two case of adding RE and not adding RE was carried out phase analysis of X-ray ,SEM observation and spectrum analysis. The former indicated that RE element was actually adulterated into the steel;the later indicated that in the added RE penetration layer,nitride was smaller,its direction was changed along depth. It was maybe because of the special effect of RE that made the performance of H13 steel be improved by surface procession.This paper relatively systemically studied the technics of H13 steel added RE surface procession and tried to find the optimum technology pattern. In the end of the paper,the writer's study work was generalized,the study direction and some problem which should be solved farther in future were discussed.