摘要
介绍了激冷球铁凸轮轴的熔炼工艺及技术要求,研究了冷铁、原铁液过冷度、浇注温度、浇注速度、浇注系统对激冷球铁凸轮轴组织和硬度的影响。最终得出结论:(1)采用与单片凸轮质量之比为3倍的冷铁,对激冷球铁凸轮轴是较为适宜的;(2)只要化学成分相同,炉料配比、炉前过热温度和过热时间对激冷球铁凸轮轴材料并无大的影响;(3)在不产生气孔、冷隔等铸造缺陷条件下,采用尽可能低的浇注温度,有利于激冷球铁凸轮轴的材料性能;(4)在不出现气孔、砂眼等铸造缺陷条件下,尽可能缩短充型时间,可提高凸轮平均硬度,且同一凸轮轴的12个凸轮硬度均匀性提高;(5)减小紊流,防止冷铁被冒口预热,可解决凸轮轴部分凸轮硬度偏低的问题。
Smelting process and the technical requirements of chilled ductile iron camshaft was introduced. The effects of chiller,original iron melt subcooling,pouring temperature,casting speed and pouring system on chilled ductile iron camshaft microstructure and hardness were studied. The conclusions were drawn as follows：it was suitable to use chiller in amount of 3times than that of single cam. It was benefit to the chilled ductile iron camshaft. The burden ratio,furnace temperature,overheating temperature and pried before melt had little had less effect on chilled ductile iron camshaft material as long as the final chemical compositions were identical. The lower pouring temperature was beneficial to the chilled ductile iron camshaft material performance as long as no stomatal or cold shut formed. Short filling time could increased the average hardness of cam as long as no air hole or blowhole formed. In addition,the hardness of 12 cams on the same shaft increased uniformity. Reducing turbulence could prevent chillers from preheating. This could fix the problem of the low hardness of some cams on one shaft.
出处
《现代铸铁》
CAS
2014年第5期25-30,共6页
Modern Cast Iron
关键词
球墨铸铁
凸轮轴
激冷层硬度
ductile iron
camshaft
chilled layer hardness
