Abstract: A casting C obtained by solidification of molten metal by using a pair of water cooled casting rolls 2a, 2b is subjected to temperature adjustment in a temperature zone so that an austenite structure exists in its matrix. Thereafter, the casting is rolled by an in-line rolling mill 5 at a temperature ranging from 850.degree. C. to less than 1,350.degree. C. and at a reduction of 5 to 50%. In this way, overall variance of elongation of the steel material is kept within 5% in terms of the standard deviation.

Abstract: The present invention provides a thin cast strip or a thin steel sheet having good cast strip properties and mechanical properties from a molten steel containing a large amount of iron scrap containing Cu and Sn. The thin cast strip or thin steel sheet is characterized by being a thin cast strip or thin steel sheet of a common carbon steel comprising 0.15 to 10% by weight of Cu and 0.03 to 0.5% by weight of Sn, the primary dendrite spacing on a surface layer portion being in the range of from 5 to 100 .mu.m.

Abstract: A twin roll-type sheet continuous casting apparatus includes a nozzle for supplying molten metal; a pair of casting rolls for casting the molten metal supplied from the nozzle into a sheet, the casting rolls being horizontally disposed in parallel relation to each other, being cooled, and rotated in opposite directions, respectively; a coiler; and a support sheet extending generally horizontally below the pair of casting rolls for receiving the cast sheet and transferring it to the coiler, and being taken up by the coiler along with the cast sheet placed therein. Since tension is not applied to the cast sheet, even a brittle material can be continuously cast into a sheet. Also, a dummy sheet requested for starting the casting of the sheet becomes unnecessary, and even when a rupture of the sheet occurs, the apparatus can be continuously operated without stopping the operation.

Abstract: A twin belt continuous casting machine for producing thin slabs includes a pair of belts and a pair of edge dams for forming a metal pool, which are movable in the transverse direction of the belt. A plurality of cooling/heating chambers partitioned in the transverse direction of the belt are provided on the rear surface of the belt in the vicinity of respective side end portions of the belts. A plurality of supporting members which are capable of pressing the rear surface of the belt are respectively provided in the plurality of cooling/heating chambers. The movement of the edge dams is synchronized with the operation of the plurality of supporting members. A fluid introduced into each of the cooling/heating chambers is changed into a heating fluid or a cooling fluid in synchronism with the movement of the edge dams.

Abstract: A continuous casting machine has a mold of a rectangular cross-section having short sides formed by parallel runs of a pair of metallic belts and short sides constituted by parallel runs of a pair of endless loops each comprising a plurality of dam blocks. The parallel runs of each endless loop are guided by inner and outer guide rails sandwiched between the edges of the parallel runs of the metallic belts and moved in the same direction as the movements of the metallic belts and substantially in synchronism therewith. So as to vary the widthwise dimension of a slab to be cast by the mold, the inner and outer guide rails are independently movable. The endless loop comprises first and second groups of dam blocks which groups are respectively shifted widthwise of the slab by one of the guide rails and by the other guide rail, whereby the width of the slab can be varied perpendicularly to the length of the slab being cast.

Abstract: A quicklime is treated by CO.sub.2 gas so as to form a CaCO.sub.3 film on the surface of the particle thereof. It serves to prevent moisture absorption so that a steel making process, especially for the production of low hydrogen steel, can be done very effectively with low cost by the use of this CO.sub.2 -treated lime.