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.