Riser size reduction and/or metal quality improving in gravity casting of shaped products by moving electric arc

摘要

The invention invention provides an apparatus (10) and a method for reducing the volume of risers, and for the possibility of reducing shrinkage blowhole and porosity in shaped gravity casting. The invention provides an apparatus (10) for producing metal flow/stir in the liquid metal (31), the apparatus (10) comprising at least one electrode (16) for forming a continuously-moving plasma arc (34) over the upper surface of selected riser(s) (12) in metallic casting being cast; a stand (26) for suspending said plasma arc electrode (16) over the upper surface of said risers (12) during the casting process, a second electrode (28) attachable to the liquid metal (31) or the metal being used for casting and a power supply (36) for completion of an electric circuit including said plasma arc (34); and control means (38) connected between said apparatus (10) and said power supply (36).