【摘要】 球墨铸铁轧辊采用普通砂型冒口补缩所消耗的金属重量约占轧辊毛重的15％。采用铝型膨胀发热剂与绝热套组合的发热保温冒口,可节约冒口金属量约20～50％,经大量生产证明,这种发热保温冒口经济效益显著。更多还原

【Abstract】 In practice,using sand open risers and pouring hot.molten metal into it once or twice every20～25 minutes after pouring to compensate the volmue contraction of spheroidal graphite castiron rolls is very common.This method consumes a large quantitty of metal for riser,which isabout 15％ of the gross weight of the rolls.In order to save metal and to improve the quality ofthe upper edge of roll barrel,we made use of the riser covered with Al—exothermic compound,incombination with insulating sleeve instead of previous procedure in which straw ash heat insulatorwas used to cover the dry-sand open riser.The results of experiment showed that the eutectictrasformation time of spheroidal graphite cast iron elongated by 33～62％;shrinkage cavity trans-forms from conical-shape to basin-shape.The hight of denser part increased,and the riser hightmight be decreased by adout 25～50％.As a result,the riser metal can be saved up to 20～50％.Itcan be concluded that using the exothermic insulating riser is most efficient and advantageous forthe production of spheroidal graphite cast iron rolls.更多还原