METHOD OF PRODUCING RISER-FREE INGOTS AND DEVICE FOR ITS REALIZATION Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: method of producing riser-free ingots consists in oriented layer- by- layer hardening of layers during electroslag heating. The novel feature is that the electroslag heating in the upper part of chiller and blowing of metal with inert gases is combined with the layer-by-layer hardening of interior cavities of ingot and their treatment by oriented concentrated electromagnetic fields, and that the formed layers are pressed by the chiller against one another by the force exceeding the yield point of metal at a temperature of crystallization and are held in this state till relaxation of occurring stresses. In the device for obtaining such ingots the working surface is in the form of cone with apex angle exceeding 45 deg and the interior cooled cavity carries solenoid mounted on ferromagnetic core and combined with the coaxial electrode and interior chiller into a single electromagnetic system. EFFECT: higher quality of riser-free ingots due to obtaining physical and chemical homogeneity of fine crystalline structure over the entire cross section of large-size ingot due to intensive cooling of crystallizing metal layers. 2 cl, 1 dwg