First, the design process of castings. When designing, in addition to determining the geometry and size of the casting according to the working conditions and the performance of the metal material, it is also necessary to consider the rationality of the design from the perspective of the casting alloy and the casting process characteristics, that is, the obvious size effect and solidification, shrinkage, stress and other problems, in order to avoid or reduce the generation of defects such as segregation, defomesen na kreking bilong komposesen bilong kasting.
Namba tu, i mas i gat wanpela gutpela wok bilong kasting i save kamap . Em olsem, bihainim straksa, hevi na sais bilong kasting, kasting aloi mak na ol kondisen bilong prodaksen, makim stretpela hap na seip bilong hap, as rot bilong wokim, na putim as bilong kasting bar, kol ain, riser na kapsaitim sistem. Long lukim olsem i gat gutpela kasting{2}} .
Third, the quality of the raw materials used in casting. The quality of metal charge, refractory, fuel, flux, modifier, casting sand, sand binder, paint and other materials is not up to standard, which will cause defects such as pores, pinholes, slag inclusion, sand, etc., affecting the appearance quality and internal quality of castings, and will cause castings to be scrapped in serious kes. Namba foa em i proses operesen, long kamapim ol stretpela proses operesen prosedur, kamapim gut teknikel level bilong ol wokmanmeri, bai ol proses prosedur i kamap stret.
