防止高强度灰铸铁气缸盖缩松缺陷的工艺研究(2)

Casting Method Investigation on Preventing Shrinkage Porosities Defects of High Strength Gray Iron Cylinder Head(Ⅱ)

介绍了TCD发动机气缸盖铸件的结构及技术要求,针对采用原铸造工艺生产该铸件过程中出现的缩松问题,从缩松产生机理、气缸盖结构、浇注系统设计、凝固过程、金相组织、力学性能、气密性检测和解剖等方面进行了分析,对影响缩松缺陷的铸件结构、化学成分、浇注系统等关键因素和局部激冷工艺进行了系统性的研究,最终确定了优化方案。经实际生产验证,气缸盖铸件的缩松废品率由60%降到0.5%~1%,有效解决了铸件缩松废品率高的问题。

The cylinder head casting structure and technical requirements of TCD engine were introduced.In order to solve the shrinkage porosities problem of castings produced with original method,the porosities formation mechanism,cylinder head structure,gating system design,solidification process,metallographic structure,mechanical properties,gas tightness detection and dissection were analyzed.The key factors including the casting structure,chemical composition,gating system and the local chilling process were studied systematically,the optimization scheme was finally determined.According to the actual production verification,the shrinkage porosities scrap rate of cylinder head casting was reduced from 60%to 0.5%~1%,which effectively solved the problem of high shrinkage porosities scrap rate.