文档介绍：=asdiscussedearlier,asmentioned,wedefinecastironsastheferrousalloyswithgreaterthan2%(w)%(w)ics[iks][vis’kɔsiti]粘度,donotformundesirablesurfacefilms膜whenpoured,andundergo经历moderate适度的shrinkage收缩duringsolidificationandcooling.·[in‘fiəriə]paredtowrought精细的;,,relativelysimpleshapes(infact,“wrought”simplymeans“worked”处理过的,加工过的).,,giving产生ahard,[‘fæsitid](wsi=2%~3%)promotesgraphite(C)precipitation沉淀、析出=depositionratherthancementite(Fe3C).Thesharp,pointedgraphite石墨flakes薄片contributeto促进,(w=%)ofmagnesium[‘mæg’ni:ziəm]position成分,[sfi‘rɔidəl],[’mæliəbəl]可锻的iron,whichisfirstcastaswhiteironandthenheattreatedtoproducenodular[‘nɔdjulə]:viscosity粘性shrinkage收缩porosity多孔magnesium镁malleable可锻的nodular球状的ENGLISHINMATERIALSSCIEN