The present invention relates to a radiant tube apparatus disposed in a heat treatment facility to perform a heat treatment of a strip and a method for manufacturing the same. The radiant tube apparatus includes a tube having an internal pipe, wherein the tube has a first continuous pattern and a second continuous pattern extending side by side and spaced apart from each other at a predetermined distance on a surface, and, in each of the first continuous pattern and the second continuous pattern, a plurality of unit patterns having a predetermined height from the surface are connected to each other in a longitudinal direction.

An method of manufacturing a hot press-formed member comprises heating a blank of an aluminum-based plated steel sheet in a heating furnace, removing the heated blank from the heating furnace and conveying the removed blank between an upper mold portion and a lower mold portion of a mold, mounted on a press, to be seated; and performing a forming process after the upper mold portion of the mold is in contact with the seated blank.

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).

A method of production non grain-oriented Fe—Si steel sheet is provided. The method includes the steps of melting a steel composition that contains in weight percentage: C≤0.006, 2.0≤Si≤5.0, 0.1≤Al≤3.0, 0.1≤Mn≤3.0, N≤0.006, 0.04≤Sn≤0.2, S≤0.005, P≤0.2, Ti≤0.01, the balance being Fe and other inevitable impurities, casting said melt into a slab, reheating said slab, hot rolling said slab, coiling said hot rolled steel, optionally annealing the hot rolled steel, cold rolling, annealing and cooling the cold rolled steel down to room temperature.

The present invention relates to a method for the manufacture of a coated steel sheet comprising the following successive steps: A. the coating of the steel sheet with a first coating consisting of nickel and having a thickness between 600 nm and 1400 nm, the steel sheet having the following composition in weight: 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb≤0.5%, B≤0.010%, Cr≤1.0%, Mo≤0.50%, Ni≤1.0%, Ti≤0.5%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, B. the recrystallization annealing at a temperature between 820 to 1200° C., C. the coating with a second coating based on zinc not comprising nickel.

A radiant element for heating an oven is disclosed. The radiant element comprises a first end; a second free end; a radiant structure between said first end and second end; a conduit for an energy feed inside said radiant structure; a first attachment leg for mechanically coupling the radiant structure to a support, a first coupling means comprising a first portion arranged to be stationary with respect to said support, and a second portion stationary relative to said first leg, the first portion and the second portion being mechanically coupled via a first interface so as to allow a relative displacement between the first portion and second portion.

A grain-oriented electrical steel sheet includes: a base steel sheet having a predetermined chemical composition; a glass coating provided on the surface of the base steel sheet; and a tension-applying insulation coating provided on the surface of the glass coating, in which linear thermal strains having, a predetermined angle (φ) with respect to a transverse direction which is a direction orthogonal to a rolling direction are periodically formed on the surface of the tension-applying insulation coating at predetermined intervals along the rolling direction, a full width at half maximum F1 on the linear thermal strain and a full width at half maximum F2 at an intermediate position between the two linear thermal strains adjacent to each other satisfy 0.00<(F1−F2)/F2≤0.15, the width of the linear thermal strain is 10 μm or more and 300 μm or less, and in the base steel sheet, an orientation distribution angle γ around a rolling direction axis of secondary recrystallization grains, an orientation distribution angle α around an axis parallel to a normal direction, and an orientation distribution angle β around an axis perpendicular to each of the RD axis and the ND axis in units of ° satisfy 1.0≤γ≤8.0 and 0.0≤(α.sup.2+β.sup.2).sup.0.5≤10.0.

A method for producing a steel strip containing, in addition to iron as the main component and unavoidable impurities, one or more of the following oxygen-affine elements in wt. %: Al: more than 0.02, Cr: more than 0.1, Mn: more than 1.3 or Si: more than 0.1, where the surface of the steel strip is cleaned, oxidation-treated and annealed. The treated and annealed steel strip is subsequently coated with a hot-dip coat. In order to be less cost-intensive and to achieve uniform, reproducible adhesion conditions for the coat, the steel strip is oxidation-treated prior to the annealing at temperatures below 200° C., where on the surface of the steel strip, with the formation of oxides with iron from the steel strip, an oxide layer is formed, which contains iron oxide and is reduction-treated during the course of the annealing under a reducing atmosphere to achieve a surface consisting substantially of metallic iron.

A direct flame furnace burner unit for furnaces for the thermo-chemical treatment of steel strips in continuous hot-dip galvanizing plants includes a burner with a combustion head provided with a combustion chamber having an outlet opening of the combustion flame, and a body to which the combustion head is fixed. The body includes a first chamber which is in communication with the combustion chamber, a first lance for the injection of a fuel into the combustion chamber, a mixing chamber provided with at least a first inlet and a second inlet opening which is connectable to a second supply source, at least a second lance for the injection of the mixture into the combustion chamber. The burner is operable in two distinct operating modes, a diffusive flame combustion mode and a premixed flame combustion mode.

A method for the recrystallisation annealing of a non-grain-oriented electric strip (2) in a continuous annealing and coating line (1) is presented. Therein, the electric strip (2) is heated in an induction furnace (5) to a temperature of at least 680° C. at a heating rate of at least 80 K/s and then, in an optional second continuous furnace (8), to a temperature of at least 820° C. at a heating rate of at most 20 K/s. The electric strip (2) is initially heated before the induction furnace (5) via a first continuous furnace (3) to a temperature of at least 300° C. at a heating rate of at most 60 K/s.