提高压铸模使用寿命的再次热处理工艺

Re-heat Treatment Process for Increasing Service Life of Die-casting Mould

通过在模具使用过程中回火和表面强化等再次热处理工艺,可及时消除应力,减缓龟裂,延长模具寿命。再次热处理的回火工艺为:将压铸模加热至比原回火温度低20～30℃保温3～4h,随炉冷却至400～450℃后出炉空冷;表面强化工艺为:气体软氮化,氮化温度550～570℃,保温4～6h,出炉后油冷或空冷,氮化层深度0.1～0.15mm,表面硬度600～900HV0.1。

Through tempering and surface strengthening heat treatment process in mold use process,the stress can be eliminated timely,cracking can be slown down,and die life can be improved.The re-heat treatment process is： heating up to 20 ℃～30 ℃ lower than the original drawing temperature,holding 3～4 h,then coolling to 400 ℃～450 ℃ following the furnace cooling and coolling in the air;the surface strengthening process is： the gas soft nitriding at 550～570 ℃,holding 4～6 h,oil-cooling or air-cooled after drawing from the furnace,nitrogen depth 0.1～0.15 mm,the surface hardness of 600～900 HV0.1.