The reason of heat treatment for Steel casting parts Steel casting parts require a major premise before using, all the casting parts need heat treatment. Parfect Casting Co.,Ltd is a exported company which mainly produces all kinds of casting steel,alloy steel,stainless steel .Now let’s talk about the reason of heat treatment for steel casting parts. All the steel casting parts need heat treatment before using. Because the internal of cast steel have some casting defects,such as pores, cracks, shrinkage, big grain size, uneven organization and residual stress,these defects reduce the strength of casting parts, especially plasticity and toughness greatly reduced.
In order to refine the grain, uniform organization and eliminate internal stress,steel casting parts need to do normalizing or annealing.After normalizing,the mechanical property is better than that of annealing ,cost is also low,so use it more.But normalizing could lead to higher internal stress than annealing,so it is just suitable for steel casting parts which C＜0.35%.Because low carbon steel casting parts have good plasticity,it isn’t easy to crack when cooling.In order to reduce internal stress,steel casting parts need to do temper after normalizing.steel casting parts which C≥ 0.35%,structure complex and easy to crack,these casting parts only need to do annealing.Steel casting parts can’t do quenching,since it will crack easily.