Defects refined in preworking. A casting has neither grain flow nor directional strength and the process cannot prevent formation of certain metallurgical defects. Preworking forge stock produces a grain flow oriented in directions requiring maximum strength. Dendritic structures, alloy segregations and like imperfections are refined in forging. More reliable, less costly.
Casting defects occur in a variety of forms.
Because hot working refines grain pattern and imparts high strength, ductility and resistance properties, forged products are more reliable. And they are manufactured without the added costs for tighter process controls and inspection that are required for casting. Better response to heat treatment. Castings require close control of melting and cooling processes because alloy segregation may occur. Forgings respond more predictably to heat treatment and offer better dimensional stability.