Abstract: A low-carbon sulfur-containing free-cutting steel having excellent cuttability which contains 0.02-0.15 mass % C, NT up to 0.004 mass % Si (excluding 0 mass %), 0.6-3 mass % Mn, 0.02-0.2 mass % P, 0.2-1 mass % S, up to 0.005 mass % Al (excluding 0 mass %), 0.008-0.04 mass % 0, and 0.002-0.03 mass % N and in which the average oxygen concentration in the MnS is 0.4 mass % or higher.

Abstract: A method for manufacturing metallic iron from a raw material mixture containing a carbonaceous reducing agent and an iron oxide-containing material, has a step of determining a target temperature of initial molten slag formation corresponding to a predetermined target carbon concentration in the metallic iron, the initial molten slag containing a gangue component, an unreduced iron oxide, and an ash component of the carbonaceous reducing agent, and being first produced in the raw material mixture by heating thereof; a step of preparing the raw material mixture producing a composition of the initial molten slag corresponding to the target temperature; and a step of heating the raw material mixture to reduce and melt the raw material mixture and to produce the initial molten slag. By this manufacturing method, metallic iron having a target carbon concentration can be efficiently manufactured.

Abstract: PROBLEM TO BE SOLVED: To provide a rotary hearth furnace which has a simple furnace structure in which the furnace is not damaged even if the furnace is operated for a long term while presenting general equations capable of adequately determining a thermal expansion margin in the rotary hearth furnace.

Abstract: A forging stock formed by extrusion such that its cross section perpendicular to the direction of extrusion varies along the direction of extrusion. The forging stock is cut into portions in the direction of extrusion to be forged individually, each cut portion having cross sections varying along the direction of extrusion. Each cut portion includes a pair of first parallel parts at both ends thereof in the direction of extrusion, a second parallel part, which is between the first parallel parts, and which differs in thickness from said first parallel parts, and oblique parts each of which is between the first parallel parts and the second parallel part.

Abstract: According to the present invention, there is provided a high strength steel sheet, which has, for example, a tensile strength of 590 to 980 MPa or more, which has favorable workability, and which is useful for an automobile, etc. The high strength steel sheet of the present invention comprises 0.03 to 0.20% C (% by mass in chemical compositions; hereafter, the same holds true), 0.50 to 2.5% Si, 0.50 to 2.5% Mn, and further, preferably 0.02 to 0.2% Mo. Moreover, its metal structure includes ferrite and low temperature transformation phase. The mean grain size of the low temperature transformation phase is 3.0 ?m or less. Further, grains whose size is 3.0 ?m or less occupy 50% or more by area ratio of the low temperature transformation phase, and an average aspect ratio of the low temperature transformation phase is 0.35 or more.

Abstract: The present invention provides a rolled material having excellent fracture splitting characteristics and suitable for the manufacture of a connecting rod in which a through-hole section for assembly in a crankshaft is fracture split in substantially semicircles. Prescribed components are contained, an average aspect ratio of a sulfide-based inclusion as observed in a D/4 portion (D is the diameter of the rolled material) in a cross-section parallel to a longitudinal direction of the rod-shaped rolled material is not more than 10.0, a Pc indicated in Equation (1) below is between 0.41 and 0.75, and a Veq indicated in Equation (2) below is not less than 0.18 mass % Pc=C(1??/100)??(1) {In Equation (1), C represents the carbon content in steel (mass %) and ? represents the ferrite fraction (area ratio %)} Veq=V+Ti/2+Si/20??(2) {In Equation (2), V, Ti and Si represent the content of each element in steel (mass %)}.

Abstract: The invention provides a press forming method of an aluminum alloy sheet and a press device capable of forming a large panel which is an automobile body outer panel such as a luggage outer panel and the like and is of a shape difficult in forming. In a method of press forming of the aluminum alloy sheet 30 into a formed product panel having non-contact outer peripheral parts 5, 6 not contacting the punch for forming the center part of the panel until the vicinity of the bottom dead point, the first punch forming the center part 2 of the panel and the second punch 15 capable of shifting independently with respect to the first punch are provided, and these punches are interlocked with each other so that the second punch 15 is made contact the non-contact outer peripheral parts 35, 36 of the sheet with the relative position of the second punch 15 with respect to the first punch 11 being shifted to the dice 22 side.

Abstract: A hot-rolled wire rod excelling in wire drawability is provided, in which breakage can be suppressed even in heavy work from a large diameter. A hot-rolled wire rod contains C: 0.35 to 0.65% (percent by mass, hereinafter expressed as well), Si: 1.4 to 3.0%, Mn: 0.10 to 1.0%, Cr: 0.1 to 2.0%, P: 0.025% or less (exclusive of 0%), S: 0.025% or less (exclusive of 0%), N: 0.006% or less (exclusive of 0%), Al: 0.1% or less (exclusive of 0%), and O: 0.0030% or less (exclusive of 0%), with the remnant consisting of Fe and inevitable impurities; wherein the content of hydrogen in steel is 2.50 ppm (ppm by mass, hereinafter expressed as well) or less, and hardness (HV) is 460×C00.1 or less (C0 indicates the content of C (percent by mass) in a position of depth of D/4 (D: diameter of the wire rod)).

Abstract: The present invention provides an aluminum alloy forging material having enhanced strength, toughness, and corrosion resistance, and a method of producing the material. An aluminum alloy forging material 1 produced with specified components under specified conditions has an arm portion 2 including a relatively narrow and thick peripheral rib 3 and a thin and relatively wide central web 4 having a thickness of 10 mm or less and having a substantially H-shaped sectional form.

Abstract: According to a process for hot-dip galvanization of the present invention, a steel sheet is treated by the oxidization/reduction method for better quality of galvanization and then hot-dip galvanized. An annealing line of equipment for hot-dip galvanization is composed of a non-oxidizing zone, an oxidizing zone, and a reducing zone, in his order. A steel sheet containing elements liable to oxidize more easily than iron is oxidized by blowing flames onto it in the oxidizing zone according to the oxidization/reduction method. Further, the steel sheet is reduced and annealed in the reducing zone.

Abstract: Provided is a method of producing an alumina film mainly in ? crystal structure superior in heat resistance, wherein the alumina film mainly in ? crystal structure is formed on a substrate, independently of the kind of the substrate at relatively low temperature, by treating the substrate surface with a ceramic powder mainly having the crystal structure same as that of alumina in the ? crystal structure, in forming the alumina film mainly in ? crystal structure on the substrate (including the substrate having a film previously formed thereon).

Abstract: A continuous kneading apparatus and method are provided wherein discharge ports are provided at a plurality of positions of the barrel to discharge a kneaded product, and one of the plurality of the discharge ports is selected according to a desired kneading condition so as to discharge the kneaded product from only the selected discharge port. Another continuous kneading apparatus and method are provided wherein a plurality of charging ports are provided at a plurality of positions of the barrel to supply a material to be kneaded into the chamber, and one of the plurality of charging ports is selected according to a desired kneading condition. The kneading apparatuses and methods permit adjustment and control of a viscosity and a dispersion degree of a compounding agent over a wide range, and continuous kneading to achieve significant rationalization of a process for producing a kneaded product.