金属型铸造缸体零件的缺陷形成及预防

Origination and Elimination of Defects in Cylinder Components in Metal Mould Casting

分析了缸体金属型铸造铸铁件缺陷形成的原因,提出了预防和改进措施。因浇注系统不合理、浇注温度低、环境湿度大等因素,使铁水氧化和含气量高;浇注操作不规范会引起气孔、夹渣、渣气孔等缺陷,在采取相应措施后可以消除或减少,通过减少石墨晶核数量和提高冷却速度,可消除石墨形态不合格;延长铸件开型时间,可减少或消除表面渗豆;铸型清洁、减少铁水氧化,可消除缓冷点;提高铁水CE、加强孕育,可消除表面夹皮;设置合适的浇注系统,可消除磷共晶带等。

The countermeasures and elimination of defects were proposed based on the analysis of the reason forming defects in cylinder components in metal mould casting.The countermeasures were applied to eliminated or reduce the gas hole,inclusion-slag and slag gas-hole resulting from un-rational gating system design,low pouring temperature and irregular pouring operation as well as high circumstance humidity leading to liquid Fe oxidation and high gas content.Reducing graphite nuclei and improving cooling rate can abolish the un-qualified graphite morphology.Sanntic sweat can be reduced or eliminated by extending mould-opened time.Cleaning cast mould and reducing liquid Fe oxidation can eliminate point of slow iron.Improving CE in liquid Fe and strengthening inoculation and abolished surface clips,and the P eutectic region can be eliminated by setting rational gating system.