AS-CONTINUOUSLY CAST BEAM BLANK AND METHOD FOR CASTING CONTINUOUSLY CAST BEAM BLANK

摘要

The present invention has a web portion and a plurality of preliminary flange portions extending in opposite directions from both tip portions of the web portion, and the ping uniform thickness of the web portion and the ping uniform thickness of each of the preliminary flange portions are formed to be 7.6 cm or less. A continuous casting beam blank in which the average thickness ratio of the preliminary flange portion to the average thickness of the web portion is between 0.5: 1 and 2: 1, a beam made by such a beam blank, and one of the web portion ends of the beam blank. It is shaped like the tip and casts a non-filled blank by injecting one stem of molten metal into the beam blank mold at a predetermined position in the mold forming the web part of the beam blank, or a beam having a shape similar to one of the tip of the web part. Molten metal is introduced into the beam blank mold at a predetermined position in the mold forming the web portion of the blank. The beam blanks were cast by separating them into stems and simultaneously injecting them. Thus, the cast blank blanks have almost no needle-like ferrite structure and a ferrite layer, but have only a fine crystal structure of ferrite and pearlite. It is about a method.