Method and apparatus for continuously casting steel

摘要

In a type of continuous casting of steel in which a straight mold is employed and a cast strand is guided while being bent, molten steel is continuously teemed into said straight mold; an unsolidified cast strand with a solidified shell formed on it is guided substantially vertically downward within a range from 3 to 7m from the meniscus of molten steel in said straight mold; then, said unsolidified cast strand being in the vertical position is guided within a range from 1 to 4m while being bent at multiple points by gradually decreasing the radius of curvature of said cast strand for each of successively arranged pairs of bending rollers; then the solidification of said unsolidified cast strand thus bent at multiple points is completed before a spot-straightening point while further guiding said cast strand along a constant curvature, the track length of said constant curvature guide being within a range from 35 to 85% of the length from said meniscus of molten steel in said straight mold up to said spot-straightening point; then, said cast strand is reduced, near its solidification completing point, at a draft of 0.1 to 2.0% per pair of reduction rolls; and then, said reduced cast strand is straightened in a substantially horizontal direction at a single point at said spot-straightening point; whereby a continuously cast strand free from or with remarkably decreased inner and outer defects is obtained.