METHOD OF PRODUCING BIMETALLIC INGOT Russian patent published in 2002 - IPC

FIELD: special electrometallurgy, more specifically, production of bimetallic ingots with use of electroslag technology. SUBSTANCE: bimetallic ingot consists of main layer from carbon, low-alloyed or alloyed steel and fused layer from corrosion-resistant steel. Method includes location of metal blank - main layer of bimetallic ingot into mold in a spaced relation to mold wall; installation of consumable electrode from corrosion-resistant steel into said gap; formation of slag bath and remelting of consumed electrode in slag bath with formation of fused layer at regulated values of formation rate and electric resistance of slag bath. Formed on main layer blank 150-300 mm thick and 1000-1600 mm wide is fused layer which thickness is 5-30% of ingot total thickness at rate set in compliance with relationship Vf= (1150-20 D)± 200, kg/h; where Vf is rate of fused layer formation, kg/h; D is thickness of fused layer, % of ingot total thickness, with slag bath electric resistance within 3.5-5.0 MOhm; under slag containing, wt.%: Cao, 20-30; SiO₂, 10-30; Al₂O₃, 2-15; MgO, 2-5; CaF₂ and impurities, the balance. Bimetallic ingots are designed for subsequent rolling into bimetallic strips and sheets. EFFECT: increased corrosion resistance of fused layer of bimetallic ingots, their facilitated manufacture in rolling into sheets, reduced cost of conversion of ingots into sheet rolled products with high strength and continuity of layers joint, uniform thickness and satisfactory quality of fused layer surface. 2 tbl