灰铸铁缸体缸盖非典型夹杂物缺陷案例分析

介绍了湿型砂生产条件下,灰铸铁缸体、缸盖常见的孔眼缺陷类型,指出了准确甄别夹杂物缺陷表面特征的重要性,重点阐述了非典型夹杂物缺陷的形貌特征及防止措施,得出以下结论:(1)提高涂料的常温性能和高温性能,防止涂料层在铸件成型前出现物理性脱落,是解决铸件产生涂料夹杂缺陷的前提条件;(2)严格控制砂芯原材料的发气量、加强砂芯排气是防止铸件产生气体夹杂缺陷的关键措施;(3)浇注系统与型腔之间部位的工艺间隙不容忽视,要注意防止铁液在充型过程中溢流进入型腔以及铸件固定位置产生氧化夹杂缺陷。

Non Typical Inclusions Defects Case Example Analyswas of Gray Iron Cylinder Block and Head

The hole defects types commonly occurring in green sand-produced gray iron cylinder block and head were introduced. The importance of accurately dwastinguwashing the surface characterwastics of inclusion defects was pointed out. As emphades,the morphology features of the non typical inclusions and their prevention measures were described. Following conclusions were obtained:(1)Elevating room temperature and high temperature properties of the coating to prevent physical shedding occurring before the casting forming was the prerequwasite to eliminate coating inclusion defects of the casting.(2)Strict controlling the gas evolution volume of the raw materials of sand cores,and strengthening sand cores venting were the key measures to prevent gas inclusions of the casting.(3)The technological gap between the gating system and the mold cavity should not be ignored,be cwereful to prevent the iron melt overflowing into the mold cavity during the mold-filling process and the oxide inclusions occurring in some permanent position of the casting.