CORE FOR MAKING HOLLOW INGOTS Russian patent published in 2003 - IPC

FIELD: foundry. SUBSTANCE: proposed core has hollow body, base, central member-cooler, deformable members and refractory coating. Deformable members are made in form of shell fitted with clearance around body and consisting of longitudinal sections. Two diametrically opposite sections are connected in lap with neighbor sections. Surfaces of their connection are arranged along cross axis of section. Longitudinal slots are formed between sections whose summary width over outer perimeter of shell is 1.3-1.5 times greater than linear shrinkage of poured alloy. Slots are filled with refractory mix from outer side of shell. Slots and clearance between shell and body are filled with low-melting material from inner side. Size of clearance 1.5-1.7 times exceeds linear shrinkage of ingot in radial direction. This provides free displacement of sections under action of shrinkage deformations of ingot in radial direction. Deformation of shell is prevented owing to melting of grains in clearance. Free course of shrinkage deformation of ingot provides getting of ingots of required geometric shape without contraction cracks. EFFECT: improved quality of ingots. 2 dwg