我厂在对用3cr 2W 8合金工具钢制造的压铸模进行热处理时,原来采用井式渗碳炉进行氮化处理。其工艺规范如下:1、调质:在盐浴炉中加热到1050±10℃后,油中淬火,再在箱式炉中调质720±10℃保温4小时后冷却(图1)。2、气体氮化:在井式炉内进行,使用氨气氮化,加热温度为510±10℃,保温,通氨速度按20～25%的分解率控制, I plant in the use of 3cr 2W 8 alloy tool steel die-casting mold for heat treatment, the original pit-type carburizing furnace for nitriding. The process specifications are as follows: 1, quenched and tempered: heated to 1050 ± 10 ℃ in a salt bath furnace, the oil quenched, and then tempered in a box furnace 720 ± 10 ℃ incubated for 4 hours after cooling (Figure 1). 2, gas nitriding: carried out in a pit furnace, the use of ammonia nitrogen, heating temperature of 510 ± 10 ℃, insulation, ammonia rate by 20 ~ 25% decomposition rate control,