| 摘要 |
FIELD: metallurgy. SUBSTANCE: method involves supplying metal into crystallizer; withdrawing ingot at variable speed; forming ingot with convex portions of wide faces and flat portions along their edges in crystallizer; supporting and directing ingot under crystallizer through secondary cooling zone by idle and drive rollers; cooling ingot surface by coolant sprinkled by nozzles. During pouring, ingot wide faces are formed in parallel one with the other lengthwise of crystallizer. Convex portions of wide faces have flat portions with width equal to 0.2-0.3 of convex portion width. Upon exit of ingot from crystallizer, convex portions of wide faces are deformed by rollers, which are brought one to the other, with deformation process being terminated at distance from metal meniscus in crystallizer equal to τ V, where t is complete hardening time of ingot having thickness equal to that of flat portions extending along ingot edges, min; V is ingot withdrawal speed, m/min. Apparatus has crystallizer with convex working cavity in the middle part of wide working walls, flat portions along their edges and thin working walls, idle and drive rollers positioned in secondary cooling zone under crystallizer. Convex portions of wide working walls extend along crystallizer length and are provided with flat portions positioned in their middle part. Roller barrels have concave middle portions with flat parts. Width of concave portion is equal to that of convex portion of crystallizer wide walls. Distance between cylindrical edge portions of barrels of each pair of rollers is made uniform and equal to width h of narrow walls of crystallizer at its lower end. Distance between flat parts of concave portion of barrels in each pair of rollers is variable from maximum value of H under crystallizer to minimum value of h at the end of cooling zone. Rollers have reciprocal drive moving them for value of 0.5 (H-h). EFFECT: increased efficiency and improved quality of ingots. |
