Abstract: A method for continuous casting metal products under utilization of a mold and pouring molten metal into the mold to obtain a flat stock with a thickness below 100 mm, includes withdrawing the partially solidified casting by at least one roll pair which reduce the thickness of the stock upstream from complete solidification by at least 10% but not more than 70% while further reduction in thickness by at least 30% obtains downstream from complete solidification is improved by requiring that the product being cast has a thickness not below 50 mm; that exclusively internally cooled rollers are used for obtaining the reduction; and that the thickness is reduced downstream from the complete solidification at a point where the temperature is only little below the solidus temperature particularly in the case of steel being a temperature between 1500 and 1200 degrees C.

Abstract: The invention relates to a method of producing a steel strip having a thickness of less than 10 mm by the casting of a steel strand in a cooled continuous ingot mould. After leaving the ingot mould and until the welding of the inner walls of the already solidified strand shell, the not yet thoroughly solidified steel strand is compressed, the thickness of the strand shell being reduced with a degree of deformation of >40%. FIG. 2 is intended for the Abstract.

Abstract: A rolling installation comprises a continuous casting machine, and a light thickness-reduction rolling mill, a width-reduction rolling mill and a thickness-reduction rolling mill which are arranged downstream of the continuous casting machine. The light thickness-reduction rolling mill is driven with a power lower than that required for thickness-reduction rolling by the light thickness-reduction rolling mill. The power deficiency is supplied to the light thickness-reduction rolling mill by the thickness-reduction rolling mill through the cast strip. As a result, a longitudinal tension is applied to the cast strip passing through the width-reduction rolling mill, thereby preventing the cast strip from being buckled and deformed at the width-reduction rolling.

Abstract: A method for the in-line homogenization and recrystallization of a continuous casting product by providing a continuous casting product including an alloy having a plurality of phases therein disposed proximate to the surface of the product and forming a plurality of voids at least near the surface by superficially cold-working the product. The surface is homogenized by heat treating and substantially reducing at least one of the phases whereby a portion of the voids assist in accelerating the diffusion of a portion of the voids into the alloy.

Abstract: A steel strand having a thickness of 40 to 50 mm in cast in an oscillating mold for continuous casting at a speed of 2 to 20 m/min. The not yet completely solidified steel strand emerging from the mold is squeezed to such an extent that the inner walls of the already solidified strand shell are welded to one another. After the steel strand reduced in thickness in this way has been cooled to 1000.degree. to 1200.degree. C., the strip is rolled out in at least one pass with a 5 to 85% degree of deformation.

Abstract: A method of continuous compression forging, with a compression forging anvil, the final solidified region of cast steel drawn out from a mold for continuously casting, comprising the step of: compressing said cast steel with said anvil at a compressing cycle which meets the following conditions: ##EQU1## where t: the compressing cycle (sec), .delta.: the overall thickness reduction, Vc: the casting speed (mm), D: the cast steel thickness before compression forging, .theta.: the inclination angle (.degree.) with respect to the flat surface of the anvil.

Abstract: A process and machine for the continuous casting of thin steel products, in which the inner casting space (13) of the mold (1) is given a substantially spindle-shaped cross-section which forms a central part (17) of large thickness (L), making it possible to introduce a jet of molten metal under normal conditions, and having on its sides (18) a small thickness (1) corresponding to that of the product to be produced (53). In a thickness-reducing stand (2) directly at the exit of the mold (1), the central part (17) of the product is progressively flattened to a thickness (1) equal to that of the sides.

Abstract: A protective device for use in a continuous casting and rolling process for protecting an eddy current detectoor. A rod arresting means is actuated when a break in the continuous rod or bar is detected. This prevents rod having fins or projections from passing into and damaging an eddy current detector.

Abstract: A segregation preventive or eliminative operation in a continuous casting process is performed under the following conditions:The solidified/unsolidified ratio of the solidifying block is in a range of 0.5:1 to 0.9:1;The ratio between the overall compression .delta. (mm) versus thickness of the unsolidified area in the block (d mm) is greater than or equal to 0.5 or the thickness (d mm) of the unsolidified layer in the solidifying block is: ##EQU1## where D is the thickness of the block before compression. Casting speed may be controlled according to thickness of the solidifying shell at or near a crater end. Preferably, electromagnetic stirring is performed before performing compression forging.

Abstract: Method of and apparatus for continuously reducing oxides which form on the surface of copper bar and rod during casting including means for collecting cleaning mixture vapors; means for raising the temperature and pressure of the collected vapor; means for lowering the temperature of the collected vapor below the temperature at which the vapor will condense without lowering the system pressure; and means for separating condensed cleaning mixture from uncondensed vapor as the uncondensed vapor is being conveyed to a furnace or other means for oxidizing residual vapor.

Abstract: In a continuously cast piece of austenitic stainless steel having a large amount of Mo, segregation of alloy elements such as Mo and Cr is caused at the center part in the thickness direction of the slab, and the .sigma.-phase is precipitated during the step of cooling the cast piece. When a heavy plate or hot coil is prepared from this cast piece as the starting material, cracking occurs in the hot-working step and the corrosion resistance of the final product is degraded. According to the present invention, at the cast piece-forming step, the super-heating degree of the molten steel is controlled to at least 25.degree. C., whereby the equiaxed zone ratio is controlled to below 25%. When the heating times at the soaking and hot rolling treatments and the conditions for annealing the obtained steel sheet are controlled, the pitting resistance of the steel plate is greatly improved and cracking is prevented at the hot-working step.

Abstract: A method is provided for producing high purity electrolytic copper useful, for example, to make a copper wire for use in sound or image reproducing systems, such as audio, video and television systems, etc. The copper wire consists of high purity copper in which silver and sulfur contents are both not more than 0.5 ppm and preferably has a crystal grain size not less than 0.02 mm and is unidirectionally solidified or is a single crystal. Such a copper wire is manufactured by continuously casting electrodeposited copper which has been obtained by refining by re-electrolysis of electrolytic copper, using a specially arranged casting apparatus having a mold projecting to an electrolytic bath.

Abstract: A method of producing steel plate with good low-temperature toughness comprises the steps of casting a steel melt consisting of 0.001-0.300 wt % C, not more than 0.8 wt % Si, 0.4-2.0 wt % Mn, not more than 0.007 wt % Al, 0.0010-0.0100 wt % O and the remainder of iron and unavoidable, impurities, and subjecting the cast steel either as it is or after rolling at a small reduction ration to accelerated cooling. In the cooling step, a fine-grained acicular ferrite texture having oxide-system inclusions as the nuclei develops radially and provides the resulting steel plate with excellent low-temperature toughness.

Abstract: A casting/rolling installation has a continuous casting machine, a light thickness-reduction rolling mill, a width-reduction rolling mill and a thickness-reduction rolling mill which are arranged downstream of the continuous casting machine. The light thickness-reduction rolling mill is driven with a power lower than that normally required for thickness-reduction rolling. The power needed to compensate for the resultant deficiency is supplied to the light thickness-reduction rolling mill by the thickness-reduction rolling mill through the cast strip. As a result, a longitudinal tension is applied to the cast strip as it passes through the width-reduction rolling mill, thereby preventing the cast strip from buckling and being deformed at the width-reduction rolling mill.

Abstract: An improved process for continuously casting a strand of steel comprising the bending of the steel with at least one corrugated roll. The strand is preferably pushed between a corrugated roll and a smooth roll by gravity or drive rolls to impact only compressive stresses to the strand. A curved strand cast with a curved mold can be straightened between two corrugated rolls having different surface corrugations to impart compressive stresses.

Abstract: A method of continuous casting of ingots having a cross section with a high width to height or thickness ratio includes the steps of using a mold with a corresponding cross section and a casting pipe with bottom or near-bottom outlets and having laterally a minimum distance from the wall of the mold; preheating the casting pipe prior to casting to a temperature being at least approximately similar to the temperature of the metal later to be poured into the mold; initially closing the bottom outlet of the mold prior to startup; pouring molten metal into the mold for filling the mold up to a particular level while continuing heating the casting pipe; commencing withdrawal of an ingot from the mold along a curved path when the level of molten metal in the mold has reached the level of the outlet or outlets of the casting pipe.

Abstract: A process and apparatus for making hot-rolled steel strip from a striplike continuously cast starting material uses successive processing steps in which the striplike cast starting material after solidification is brought to the hot rolling temperature and fed to a multi-stand rolling mill for rolling to the finished rolled product. A continuous casting unit supplies the multi-stand rolling mill. The rolling to the finished rolled product occurs continuously in three or four roll stands to achieve the largest possible reduction per pass. The first two roll stands operate with an approximately maximum rolling moment and a large working roll diameter.

Abstract: Continuous casting of metal is optimumly practiced by pouring a casting configured with a trapezoidal cross-section, which issues from the bottom of a mold curvilinearly directed to horizontal extension where it is passed between vertically aligned squeeze rolls which compressively deform and narrow the cross-sectional configuration from trapezoidal to rectilinear and thereby straighten and true the casting for being pinched-off and sectioned to length while the core of the casting is molten. The inventive method and means avoids tensilely stressing the casting, lessening the risk that the skin of the casting will rupture from being stretched and that molten metal from the core of the casting will spill endangering personnel and equipment and ruining the casting.

Abstract: A substrate for a lithographic printing plate is made of a rolled aluminum alloy sheet of following composition: 0.8 to 2.0% Fe, up to 0.8% Si and up to 1.0% Mn, such that the sum of the Si and Mn contents lies between 0.3 and 1.3%, up to 0.3% Cu, up to 0.8% Mg, up to 2.0% Zn and 0.3% each of other constituents in total up to 1.0%, rest aluminum. A process for manufacturing such a substrate is such that this composition is cast as a 5 to 12 mm thick strip then fabricated to a 0.03 to 0.6 mm thick rolled sheet.

Abstract: Thin steel sheets having an improved processability are produced when a steel sheet or cast strip obtained through a continuous casting or strip caster process is subjected to a lubrication rolling step at a temperature of from Ar.sub.3 transformation point to 300.degree. C. and a rolling speed of not less than 1,500 m/min. By this method, the cold rolling step or cold rolling-annealing step can be omitted.

Abstract: An apparatus and process for the continuous casting of tubular shapes wherein molten metal from which the tubular shape is formed is centrifugally deposited adjacent to the outlet of a fluid-cooled mold by a nozzle assembly, with the metal being cooled and rapidly solidified by the mold to form a cylindrical shell upon which additional metal is deposited to incrementally build the thickness of the tubular shape. The tubular shape being formed is withdrawn continuously from the mold, and is further cooled by coolant directed thereon. The nozzle assembly may be rotated to discharge the molten metal or, alternatively, the mold may be rotated as the metal is deposited thereon. Single-layer tubular shapes, with or without reinforcing material, may be cast and multiple-layer composite shapes may be produced having layers of different material composition and thicknesses. An inert atmosphere is maintained to prevent oxidation of the molten metal.

Abstract: A method and apparatus for producing a rapidly solidified microcrystalline metallic tape. The method provides for molten metal to be continuously poured through a nozzle onto surfaces of cooling members to form a rapidly solidified metallic tape and then coiling the tape on a reel. According to this method, the metallic tape is secondarily cooled and rolled before the coiling. The apparatus includes a device for cutting out a non-steadly portion of the metallic tape, a device for measuring tape thickness, a secondary cooling member, and a device for controlling the tension of the metallic tape.

Abstract: A process for producing copper rod having an improved surface smoothness and substantially no surface oxides, which rod is suitable for drawing or rolling into wire, is disclosed. The process comprises the steps of forming a bath of molten pure copper, casting the molten copper into a cast bar, conditioning the bar for hot-rolling, hot-rolling the bar to form a hot-rolled rod, cooling the hot-rolled rod and chemically shaving and pickling the hot-rolled rod. The chemical shaving and pickling step is performed with a solution containing controlled concentrations of sulfuric acid and hydrogen peroxide. Both the solution and the rod are maintained at elevated temperatures and the duration of the reaction is controlled. The interrelated process variables are regulated so that substantially all of the surface oxides and a desired amount of copper are removed from the surface of the hot-rolled rod.

Abstract: A method of continuously casting molten metal by continuously drawing a strand, wherein the thickness of said strand is continuously reduced at a reduction rate (x) in a region between a point of time when the center of said strand has a temperature corresponding to a solid-phase ratio of 0.1 to 0.3 and a point of time when said temperature has dropped to a level corresponding to a solid-phase ratio at a limit of fluidization, provided that said reduction rate (x) satisfies the following equation (1):0.6.xi..ltoreq.x.ltoreq.1.1.xi. (1)where.xi.=4/r, 1.cent.r.ltoreq.4,r is a flatness ratio of the strand,x is a reduction rate (mm/min).

Abstract: A method of and apparatus for continuously casting a high impurity content molten metal in a casting means and the product formed thereby. The method includes the steps of cooling said metal while in said casting means to a temperature resulting in a sound cast bar, extracting the sound cast bar from said casting machine, advancing the sound cast bar to pre-heating means, heating the sound cast bar to a hot-forming temperature, passing the cast bar at a hot-forming temperature from the pre-heating means to a hot-forming means, and hot-forming the cast bar into a wrought product without the cat bar cracking, even when the cast bar has an impurity content of from about 20 to about 200 ppm.

Abstract: This invention relates to formation of strip or other small sections by casting of metal and passing it through a sizing die. More particularly, the invention relates to production of metal strip by casting, by extruding the strip through a die and by rolling the extruded strip to a thinner gauge.

Abstract: A mold for the continuous casting of metal to a sheet-like strand is provided with a casting passage having a slot-shaped outlet end. The inlet end of the casting passage is considerably wider, and has a much larger area, than the outlet end. This facilitates pouring of molten metal into the mold and permits the use of casting techniques such as shrouding which enhance the continuous casting process and/or the quality of the strand. The cross-sectional area of the casting passage decreases progressively from the area at the inlet end to that at the outlet end over at least a portion of the length of the mold. The perimeter of the casting passage, however, remains at least approximately constant as the area decreases. This enables the strand to be drawn through the mold without difficulty. A continuous casting method involves pouring molten metal into a casting passage, and partially solidifying the molten metal to form a strand which is drawn through the casting passage.

Abstract: Fe alloy containing Si more than 4.0 wt % is produced by a thin plate casting process. The producing condition depends upon rapid solidification of Fe alloy from a molten condition at cooling rate of more than 1.degree. C./sen to less than 10.sup.5 .degree. C./sec.The obtained thin cast plates are subjected to a hot rolling of more than 30% at the temperature range of 600.degree. to 800.degree. C., and to the cold rolling to a determined thickness, followed pickling. By the above mentioned conditions, operations of the industrial scale may be practiced without cracks on the surface in the cold rolling excellent magnetic characteristics may be provided by passing the annealing after the cold rolling.

Abstract: A continuously cast slab is processed to prevent the formation of surface cracks by applying plastic strains to the surface layer of the slab in which a process of solidification is taking place. The method comprises pressing a projection against the slab surface under specified conditions prior to introducing the slab to a leveling stage.

Abstract: The Cr-series stainless steel sheet heretofore produced by a method including annealing a hot-rolled strip for decomposing the .alpha.'-phase or .gamma.-transformed phase therein, can be produced by omitting this annealing. In the method according to the present invention, a thin casting is cooled from the solidification temperature to the end temperature of the .gamma.-phase-precipitation at a cooling speed at least equal to the air cooling-speed, thereby avoiding the .gamma.-phase-precipitation. Then, the precipitation treatment for precipitating the supersaturated C, N, and S, or the heating to the .alpha.+.gamma. dual phase-temperature region for precipitating the .gamma.-phase, is carried out.

Abstract: A method is provided for removal of surface oxide from a continuously cast copper bar preparatory to inline hot rolling, wherein solidified bar continuously advancing from a continuous caster is directed to a continuous hot rolling mill, comprising: passing said advancing bar, being at hot rolling temperature, through a spray zone of selected quench capacity and impulse, such that for each segment of said bar passing through said spray zone, said oxide is quenched to a black heat but is not ablated and said underlying bar is subjected to a shallow quench; said spray zone being situated in close proximity to but selectively spaced upcourse from the first rolls of said hot rolling mill such that there is insufficient time for substantial reheating of said quenched oxide during the approach to said first rolls; whereupon as quenched segments of the advancing bar progressively approach said first rolls and said underlying bar begins to deform just prior to roll contact, said oxide spalls off the bar surfaces subs

Abstract: Continuously cast thin slab ingots are coiled, cut, uncoiled and rolled down to thin strip material. For a single casting line a single back and forth rolling stand is used; multiple continuous casting lines can service a single unidirectional rolling mill. The rolling temperature is attained by heat retention in the coils.

Abstract: An ultra-light structure is produced by continuously molding a greensand core, forming a material in the mold pattern in the core which solidifies to form a solidified framework, and removing the greensand core.

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: A method and plant for casting and rolling strip and/or sheet in line. The method comprises continuously casting slabs less than about 1.5 inches thick which naturally have a columnar grain structure. The method further comprises passing the slabs directly onto an insulated run-out table for maintaining temperature and minimizing heat loss from the slabs and permitting equalization of temperature within the slabs. The method also comprises passing the slabs directly to a hot reversing mill having upstream and downstream coiling furnaces such that the slabs first pass the reversing mill and are subject to an initial reduction in thickness sufficient to break up the columnar structure prior to being coiled as strips in the downstream coiling furnace and passing the strips back and forth to produce sheet or strip having an equiaxed grain structure.

Abstract: A method is provided for producing substantially austenitic stainless steel strip, particularly chromium-nickel grades, having ultra low sulfur levels up to 0.002% by conventionally continuously casting the slab and thereafter hot rolling the slab to hot-rolled band by improving the ability to achieve hot-rolled band having good surface quality as characterized by reduced metallurgical slivers.

Abstract: A reinforcement for rubber is disclosed, which comprises a cord made from an amorphous iron-base alloy filament previously subjected to a wire drawing at a reduction of area of not less than 10%.

Abstract: A method for producing a metallic strip is disclosed. A metallic melt containing above about 20% by weight of iron is formed into a strip so that fine iron particles are distributed throughout. The strip may be rolled to elongate the iron particles.

Abstract: A process for casting metallic strips thicker than from melt-drag processes but thinner than the inherent normal thickness of a cast melt is disclosed. The disclosed process casts molten metal, without decanting or accelerating the molten stream, onto a channel-shaped chill surface. After casting, the molten strip acquires a high thermal gradient. Following thermal shrinkage of the underside the molten top layer is squeegeed using a chill roll to uniformly distribute and crystallize the top surface.

Abstract: Apparatus for continuously forming a continuous strip of aluminum sheet material using a belt caster for forming a continuous strip of aluminum sheet material and a roll caster for immediately reducing the thickness of the continuous strip of aluminum sheet material wherein the continuous loop belt means used in the belt caster are driven by the rolls of said roll caster.

Abstract: The present invention is directed to a continuous casting process for the production of semi-finished articles or blanks of hard steels such as bars, wires or tubes having a carbon content higher than 0.75%. In this process, the blank obtained by continuous casting is submitted to a secondary cooling under the mold, cut and within three minutes after cutting, introduced into a reheating furnace in which its temperature is brought to a level slightly lower than the solidus temperature, maintained for a short period, and finally elongated in the hot condition. In a preferred embodiment, the liquid steel is stirred during the continuous casting operation by means of magnetic fields induced in the steel by electromagnetic coils disposed around the blank thereby facilitating dissolution of carbides contained within the liquid steel.

Abstract: Aluminum alloy sheet for use in drawn and ironed can bodies, having a content of 0.45-0.8% Mn, 1.1-2.2% Mg, 0.3-1.2% Fe, and 0.1-0.50% Si, produced by casting a continuous strip ingot of the alloy between chilled moving belts while maintaining a heat flux of at least about 40 cal./cm..sup.2 /sec. through the belts such that the as-cast ingot has a cell size ranging from about 10-15 microns at its surfaces to about 23-30 microns at the center of its thickness, and reducing the ingot by rolling operations including cold rolling to can body stock gauge, the cold-rolled product having a maximum constituent particle size of about 2 microns at the surface and about 3-4 microns at the center.

Abstract: Disclosed is an apparatus and method for the integrated, continuous, high speed manufacture of metallic strip, especially brass, from a melt. The apparatus comprises a chilled casting mold in liquid communication with a melt, means for drawing a rod through the mold at a constant rate and means for oscillating the mold in a pattern of forward and reverse strokes with respect to the direction of travel of the rod. Conversion of the rod to strip comprises flattening in a hot rolling mill, and quenching. In accordance with known procedures, the produced strip can be further reduced in cross section in one or more cold rolling mill or other hot rolling mills if desired.

Abstract: Extrusion apparatus comprises a rotatable wheel having an endless groove in its periphery, a fixed structure which covers part of the groove to define a passageway, a blocking member projecting into the groove to close off one end of the passageway and a die orifice leading from the closed off passageway adjacent the blocking member. The metal which is introduced into the passageway at the position away from the blocking member is in molten form and means are provided for fluid cooling at least that part of the wall of the passageway which is not defined by the fixed structure so as to solidify molten metal introduced into the passageway.

Abstract: An ultra-light structure is produced by continuously molding a green sand core, forming a material in the mold pattern in the core which solidifies to form a solidified framework, removing the green sand core and wrapping the resultant solidified framework structure in a material.

Abstract: A method of continuously casting a molten ferrous alloy in a casting means to obtain a solidifed cast bar at a hot-forming temperature, passing the cast bar at a hot-forming temperature from the casting means to a hot forming means, and hot forming the cast bar into a wrought product by a two-stage reduction of its cross-sectional area while it is still at a hot-forming temperature, including, in the first stage, the step of forming a substantially uniform fine grained, equiaxed or cell structure in the outer surface layers of the cast bar by a selected small amount of deformation of the cast bar in its as-cast condition prior to the second stage in which substantial reduction of its cross-sectional area forms the wrought product.

Abstract: The invention relates to a steel and a process for its manufacture which is suitable for the production of springs, especially leafsprings for vehicles. The steel which is vacuum-treated is an ordinary low-carbon steel with 0.20-0.04% C. Its composition is incidentally characterized in that the oxygen content does not exceed 0.040% and in that boron is added to an amount of 0.002-0.004% and titanium to an amount of 0.015-0.050%. The addition of boron causes the hardenability to increase greatly, thus making it possible to keep the carbon content low and, in consequence, reducing the danger of destructive decarbonization.A characteristic of the process of production consists in the fact that the steel is produced in an oxygen converter in such a manner that the nitrogen content in the ladle does not exceed 20 ppm, in that it is subsequently subjected to vacuum treatment and in that Al is added so that the amount of uncombined oxygen drops to max.

Abstract: A method of manufacturing a cylindrical billet having a predetermined length useable as raw material for producing a pipe. This method is practiced by way of the steps of drawing a cast slab from a casting mold on a continuous casting stand, spirally winding or cylindrically bending it around a rotating mandrel, joining together both end faces of the wound or bent cast slab to a cylindrical body and cutting it to a predetermined length. Two or more cast slabs may be used for forming the cylindrical body. Two rectangular cast slabs may be used as starting material which are subjected to roll forming and thereafter are cut to the predetermined length. They are then press worked to form a recess having a semi-circular cross-sectional configuration whereby a cylindrical body is constituted by assembly thereof in a superimposed relation.

Abstract: A process and apparatus for forming a thin-walled, elongated member having superior strength properties from an age hardenable copper base alloy is described herein. A slug or billet of a slurry cast, age hardenable copper base alloy is formed into a semi-solid slurry having about 10% to about 30% of the alloy in a liquid phase. The semi-solid slurry is then thixoforged to form the thin-walled, elongated member. Thereafter, the member is age hardened to provide a product having desired strength properties. The process and apparatus of the instant invention may be utilized to form cartridge casings.

Abstract: A method and an apparatus for removing fine cold shut cracks on a horizontally and continuously cast steel strand, using ejection of a plurality of metal shots, comprises: horizontally and intermittently withdrawing a cast steel strand from a horizontal mold by a plurality of cycles each comprising a pull and a push, cooling the cast steel strand in a cooling zone provided following the horizontal mold on the same horizontal level as that of the horizontal mold, increasing the temperature of the surface portion of the solidified shell of the cast steel strand in a heat-restoring zone provided following the cooling zone on the same horizontal level as that of the cooling zone, to soften the surface portion of the solidified shell of the cast steel strand, and then continuously ejecting a plurality of metal shots from a plurality of shooters in a shooting zone provided following the heat-restoring zone on the same horizontal level as that of the heat-restoring zone onto the cast steel strand, to weld fine cold