高速钢大圆刀的热处理

Heat Treating of Large-sized High Speed Steel Round Cutters

高速钢大圆刀外径为200~420 mm、内径为145~254 mm、厚度为5~10 mm,不仅精度要求高,硬度要求高达62.5~64 HRC,大多采用盐浴炉淬火、回火。安徽嘉龙锋钢公司对外径为310 mm、内径为190 mm、厚5 mm的W6Mo5Cr4V2钢刀具在锻后退火和去应力退火后,在保护气氛炉中加热至1175~1185℃奥氏体化和氮气冷却,随后在台车式炉中540~550℃×3 h回火3次。结果表明:大圆刀的精度和硬度均符合要求。

Large-size dhigh speed steel round tools having OD ranging from 200 to 420 mm,ID ranging from 145 to 254 mm and thickness ranging from 5 to 10 mm,besides high precision requirement,are required to have hardness as high as 62.5 to 64 HRC,and are mostly hardened and tempered in salt bath furnace.W6Mo5Cr4V2 steel tools 310 mm OD by 190 mm ID by 5 mm thick were austenitized at 1175 to 1185℃and cooled in nitrogen gas in a protective-atmosphere furnace,and then tempered 3 times at 540 to 550℃for 3 h in a car-bottom hearth furnace after annealing subsequent to forging and stress relieving in Anhui Jialong Fenggang Co.The results showed that both the precision and hardness of the large-sized round tools conformed with the requirements.