Abstract: Semi-solidified metal compositions are stably produced by pouring molten metal into a cooling agitation vessel, agitating it while cooling to produce a slurry of semi-solidified metal composition at a solid-liquid coexistent state and discharging out the semi-solidified metal composition from a discharge port of the vessel. In this case, the cooling agitation is carried out so that a relation of fraction solid, solidification rate and shear rate satisfies the following equation (1).eta.=a/2(1/f.sub.s -1/f.sub.scr).ltoreq.10 (1).

Abstract: In a process and an apparatus for stably and continuously producing a solid-liquid metal mixture in which non-dendritic primary solid particles are dispersed into the remaining liquid matrix, molten metal is charged into a clearance between a wall member and a rotating agitator composed of a cylindrical drum having a horizontally rotational axis.

Abstract: A method of the continuous casting of molten metal by continuously withdrawing a strand is disclosed. The method is characterized in that the thickness of the strand is continuously reduced at a rate of 0.5 mm/min to less than 2.5 mm/min in the region between the point of time when the center of the strand has a temperature corresponding to a solid-phase ratio being within the range of 0.1 to 0.3 and the point of time when said temperature has dropped to a level corresponding to the solid-phase ratio at the limit of fluidization, while substantially no reduction in thickness is effected in the region between the point of time when the center of the strand has a temperature corresponding to the solid-phase ratio at the limit of fluidization and the point of time when said temperature has dropped to the solidus line.

Abstract: Production of steel materials which show excellent HAZ qualities when used for welded structures and containC: 0.001 to 0.300%Mn: 0.4 to 2.0%P: 0.025% max.S: 0.025% max.Al: 0.007% max.Ti: 0.003 to 0.050%O: 0.0010 to 0.0100%Balance: iron and unavoidable impurities and containing 0.002 to 0.100% of oxide inclusion having a complex grain phase composed of one or more of Ti oxides such as TiO, Ti.sub.2 O.sub.3 having a particle size of not larger than 10 .mu.m.

Abstract: An improved converter steelmaking process that achieves a great increase in the refining capability of top-blown oxygen is provided. The process applies to an oxygen top-blowing converter that also permits bottom blowing of gas and it is characterized by supplying oxygen from a top-blowing lance and a bottom-blowing nozzle substantially throughout the refining operation, with 2 vol. % to less than 17 vol. % of a predetermined total oxygen flow rate being supplied from the bottom-blowing nozzle whereas the remaining part of oxygen is blown onto the surface of the hot metal from the top-blowing lance.