This manufacturing method for a slab is a method for manufacturing a slab by a continuous casting equipment including a twin-drum type continuous casting apparatus, a cooling apparatus, an in-line mill, and a coiling apparatus. The method includes calculating a friction coefficient from measured values of a rolling load and a forward slip when the slab is rolled, by use of a rolling analysis model, and controlling a lubrication condition during rolling of the slab so that the friction coefficient falls within a predetermined range, wherein, when the friction coefficient is calculated from the measured values of the rolling load and the forward slip by use of an Orowan theory and a deformation resistance model formula based on a Shida's approximate formula as the rolling analysis model, the predetermined range is 0.15 or more and 0.25 or less.

A dual hardness steel article comprises a first air hardenable steel alloy having a first hardness metallurgically bonded to a second air hardenable steel alloy having a second hardness. A method of manufacturing a dual hard steel article comprises providing a first air hardenable steel alloy part comprising a first mating surface and having a first part hardness, and providing a second air hardenable steel alloy part comprising a second mating surface and having a second part hardness. The first air hardenable steel alloy part is metallurgically secured to the second air hardenable steel alloy part to form a metallurgically secured assembly, and the metallurgically secured assembly is hot rolled to provide a metallurgical bond between the first mating surface and the second mating surface.

A steel sheet for cans has a chemical composition containing, by mass %, C: 0.015% or more and 0.150% or less, Si: 0.04% or less, Mn: 1.0% or more and 2.0% or less, P: 0.025% or less, S: 0.015% or less, Al: 0.01% or more and 0.10% or less, N: 0.0005% or more and less than 0.0050%, Ti: 0.003% or more and 0.015% or less, B: 0.0010% or more and 0.0040% or less, and the balance being Fe and inevitable impurities. The steel sheet has a microstructure including a ferrite phase as a main phase and at least one of a martensite phase and a retained austenite phase as a second phase, the total area fraction of the second phase being 1.0% or more, and the sheet has a tensile strength of 480 MPa or more, a total elongation of 12% or more, and a yield elongation of 2.0% or less.

[Object] To produce an H-shaped steel product with a flange width larger than a conventional flange width by, in a rough rolling step using calibers in producing H-shaped steel, creating deep splits on end surfaces of a material (e.g., slab) using projections with acute-angle tip shapes, and sequentially bending flange portions formed by the splits. [Solution] Provided is a method for producing H-shaped steel using a slab as a material. In a rolling mill that performs a rough rolling step, a plurality of calibers to shape a material to be rolled, and a web thinning caliber to thin a web of the material to be rolled that has been shaped in the plurality of calibers are engraved, the number of the plurality of calibers being three or more. Shaping of a plurality of passes is performed on the material to be rolled in part or all of the plurality of calibers. In a first caliber and a second caliber among the plurality of calibers, projections to create splits vertically with respect to a width direction of the material to be rolled are formed. In a third caliber and subsequent calibers among the plurality of calibers, a step of sequentially bending divided parts formed by the splits is performed. The projections formed in the first caliber and the second caliber have a tip angle of 40 or less.

Electric resistance welded steel pipe securing the high strength and high toughness demanded from oil well pipe in recent years. The metal structure in a region having a width of 0.5 mm in both the thickness directions from a reference point, when using a point defined as a point of the thickness in the thickness direction from the surface in the base material part of the steel as the reference point, consists of polygonal ferrite: 10 area % or less and a balance: bainitic ferrite. The thickness is 15 mm or more.

A method of delaying the process of recovery of metals, a method to make an aluminum alloy comprising zirconium, and an apparatus comprising an aluminum alloy and zirconium are provided. In some embodiments, the aluminum alloy of can be formed from recycled aluminum alloys.

A calcium-bearing magnesium and rare earth element alloy consists essentially of, in mass percent, zinc (Zn): 1-3%; aluminum (Al): 1-3%; calcium (Ca): 0.1-0.4%; gadolinium (Gd): 0.1-0.4%; yttrium (Y): 0-0.4%; manganese (Mn): 0-0.2%; and balance magnesium (Mg).

A continuous-cast slab is provided where central porosity is reduced by surly crushing the slab. A method and apparatus of manufacturing the slab is also provided. The continuous-cast slab having horizontally symmetrical granular equiaxed crystals at least in the center in the thickness direction includes a first reduction dent and a second reduction dent that further dents from the bottom surface of the first reduction dent and is narrower than the first reduction dent at least on one long side surface. Such a configuration can makes it possible to achieve the continuous-cast slab of no more than 2.510.sup.4 cm.sup.3/g in a maximum porosity volume while segregation is reduced.

A method for collecting mill scale from a hot rolling mill is provided. The hot rolling mill includes a flume. The method includes transporting mill scale particles in wastewater, retrieving the wastewater from a flume of the hot rolling mill and separating the mill scale particles from the wastewater using a separator. A hot rolling mill and a method for retrofitting a hot rolling mill are also provided.

A device and a method for producing a continuous strip-shaped composite material. For this purpose, a base material, which is produced using at least one casting machine as a continuous strand, in particular made of steel, and providing at least one cladding material, which is unwound in the form of at least one metal strip by a coil unwinding unit are provided. Subsequently, a slab which has formed by solidification from the strand produced by the casting machine and the metal strip unwound by the coil unwinding unit, in the hot state are brought together, wherein the materials, which are moved in the direction toward one another, formed from the slab and the unwound metal strip are hot rolled, so that a single continuous strip-shaped composite material is thus produced by roll cladding. The base material is continuously cast in the vertical direction in the casting direction.