我厂十多年来,一直沿用旧的铁模薄涂料汽缸体离心浇铸工艺。由于铁模的急冷,铸件虽经920～1000℃高温退火,其金相组织里还有点状过冷石墨及游离碳化物而达不到国家标准。六四年经摸索、试验,成功地采用了以废面粉(面粉厂下脚料)为粘结剂的新涂料。这种涂料由75～80%的细砂(通过40目筛)和25～20%废面粉(经半分筛去块)配制而成。配制好的涂料由定量勺倒入控制在350～450℃的离心机铁模中(铁模內表面呈暗红色)。此时涂料中的废面粉燃烧炭 I plant more than 10 years, has been using the old iron thin coating cylinder block centrifugal casting process. Due to the rapid cooling of the iron mold, although the castings are annealed at a temperature of 920 to 1000 ° C, the metallurgical structure still has point-like supercooling graphite and free carbides that fail to meet the national standards. In 1964, after exploring, testing and successfully adopting a new coating made of waste flour (flour mill scraps) as a binder, This paint is made of 75-80% fine sand (through a 40 mesh screen) and 25-20% waste flour (removed by half screen). Preparation of a good paint from the quantitative spoon into the control of the centrifuge iron mold 350 ~ 450 (iron mold surface was dark red). The waste flour in the coating at this time burns charcoal