The housing castings produced with former casting method had defect revealed by magnetic traces congregation which were analyzed with numeral simulation software and concluded that the defects were the oxide inclusion caused due to the turbulence and splash of the mold-filling iron melt stream and the oxide dross which was formed in the later mold-filling period and then floated to the surface layer and congregated. At last,by adopting bottom gating system,keeping the ingates from striking the mold and core, ensuring enough filling space in the front of filling stream, setting filter before the ingates, and setting nodular iron -special exothermic risers on the hot spots etc., the secondary oxide dross inclusion. was effectively eliminated and the shrinkage defect was also prevented and so that the process yield was increased.%原工艺产生的铸件表面有磁痕聚集缺陷,利用数值模拟软件分析后,认为原因是充型过程中的紊流和飞溅导致大量氧化夹杂,以及充型后期铁液中氧化渣上浮、聚集所致.最后采取底注方式,浇注位置避开铸型和砂芯,充型前方预留足够的充型空间,内浇道前方设置陶瓷过滤网,铸件热节部位采用球铁专用发热冒口等措施,有效地解决二次氧化夹渣导致的磁痕缺陷,并防止了缩松缺陷的产生,工艺出品率得以提高.
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