The resul ts indicated that there exists obvious gas gap in molten iron flowing front, and the pressure in gas gap with EPS pattern during vacuum pouring is less than 1 a tm.

• 试验结果表明，铸铁件流动前沿不仅存在明显的气隙，而且采用聚苯乙烯模样材料，负压下浇注时，其气隙压力低于1个大气压。