C21D8/005

HOT-STAMPING FORMED BODY
20230079854 · 2023-03-16 · ·

A hot-stamping formed body includes a steel sheet and a zinc-plated layer that is provided on the steel sheet. The steel sheet has a predetermined chemical composition, and an area % of martensite is 90% or more in microstructure at a position corresponding to ¼ of a sheet thickness of the steel sheet from a surface of the steel sheet in a sheet thickness direction. The zinc-plated layer includes a F phase and a Fe—Zn solid solution, and a cross-sectional area ratio of voids present in the zinc-plated layer is 15.0% or less.

LOW THERMAL EXPANSION CAST STEEL AND METHOD OF PRODUCTION OF SAME

An object of the present invention is to provide a low thermal expansion cast steel having a high yield strength at room temperature, a high rigidity, and a low coefficient of thermal expansion. The low thermal expansion cast steel of the present invention is obtained by suitably heat treating a cast steel comprising, by mass %, C: 0 to 0.1%, Si: 0 to 0.5%, Mn: 0 to 0.5%, S: 0 to 0.05%, Ni: 29.0 to 34.0%, Co: 0 to 8%, and a balance of Fe and unavoidable impurities so that the 0.2% proof stress becomes 350 MPa or more, the Young's modulus becomes 130 GPa or more, and the average coefficient of thermal expansion at 18 to 28° C. becomes 2.0×10.sup.−6/° C. or less.

High strength austenitic stainless steel having excellent resistance to hydrogen embrittlement, method for manufacturing the same, and hydrogen equipment used for high-pressure hydrogen gas and liquid hydrogen environment

This high strength austenitic stainless steel having excellent resistance to hydrogen embrittlement includes, in terms of mass %, C: 0.2% or less, Si: 0.2% to 1.5%, Mn: 0.5% to 2.5%, P: 0.06% or less, S: 0.008% or less, Ni: 10.0% to 20.0%, Cr: 16.0% to 25.0%, Mo: 3.5% or less, Cu: 3.5% or less, N: 0.01% to 0.50%; and O: 0.015% or less, with the balance being Fe and unavoidable impurities, in which an average size of precipitates is 100 nm or less and an amount of the precipitates is 0.001% to 1.0% in terms of mass %.

Quench and temper corrosion resistant steel alloy and method for producing the alloy

A quench and temper steel alloy is disclosed having the following composition in weight percent. TABLE-US-00001 C 0.1-0.4 Mn 0.1-1.0 Si 0.1-1.2 Cr 9.0-12.5 Ni 3.0-4.3 Mo   1-2 Cu 0.1-1.0 Co   1-4 W  0.2 max. V 0.1-0.6 Ti  0.1 max. Nb up to 0.01 Ta up to 0.01 Al   0-0.25 N 0.1-0.35 Ce 0.006 max. La 0.006 max.
The balance of the alloy is iron and the usual impurities found in similar grades of quench and temper steels intended for similar use or service, including not more than about 0.01% phosphorus and not more than about 0.010% sulfur. A quenched and tempered steel article made from this alloy is also disclosed. Further disclosed is a method of making the alloy.

Preparing method of engine valve

A method of preparing an engine valve is provided. The method includes hot forging a heat resistant steel at 1,150 to 1,250° C. to mold a valve, aging the molded valve and hollowed-out processing the aging valve. Additionally, the method includes nitride-heating the hollow valve and grinding a surface of a neck of the nitride-heated valve to remove a nitride layer.

Grain-oriented electrical steel sheet, annealing separator, and method for manufacturing grain-oriented electrical steel sheet

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to a base steel sheet, an annealing separator utilized for manufacture of grain-oriented electrical steel sheet, and a method for manufacturing grain-oriented electrical steel sheet are proposed. The grain-oriented electrical steel sheet is provided with a base metal steel sheet containing comprising a predetermined chemical composition and a primary coating formed on a surface of the base steel sheet and comprising Mg.sub.2SiO.sub.4 as a main constituent. The primary coating satisfies the conditions of (1) the number density D3 of the Al concentrated region: 0.020 to 0.180/μm.sup.2, (2) (total area S5 of regions which is anchoring oxide layer regions and is also Al concentrated regions)/(total area S3 of Al concentrated regions)≥33%, (3) distance H5 of mean value of length in thickness direction of regions which is anchoring oxide layer regions and is also Al concentrated regions minus H0: 0.4 to 4.0 μm, (4) (total area S1 of anchoring oxide layer regions)/(observed area S0)≥15%.

Method and apparatus for manufacturing a forged component

A method for manufacturing a forged component includes: performing hot forging on a material; heating the hot forged material to a first set temperature; and performing warm coining to correctly shape the heated material. The material may be heated to a second set temperature before hot forging. The material heated to the second set temperature may be hot forged. The second set temperature may be higher than the first set temperature. The hot forged material may be subjected to controlled cooling to a third set temperature at a predetermined cooling rate. The controlled cooled material may be heated to the first set temperature. The third set temperature may be lower than or equal to the first set temperature.

METHOD FOR MANUFACTURING A METAL SHEET WITH A ZnAl COATING AND WITH OPTIMIZED WIPING, CORRESPONDING METAL SHEET, PART AND VEHICLE

A coated metal sheet includes a steel substrate and a coating on at least one surface of the steel substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The coated metal sheet was subjected to a skin pass operation after coating. An outer surface of the metal coating has a waviness Wa.sub.0.8 of less than or equal to 0.55 μm.

RAILWAY WHEEL
20230119875 · 2023-04-20 ·

A railway wheel in which formation of a quenched layer can be suppressed in the production process is provided. The railway wheel according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.80 to 1.15%, Si: 1.00% or less, Mn: 0.10 to 1.20%, P: 0.050% or less, S: 0.030% or less, Al: 0.005 to 0.190%, N: 0.0200% or less, Nb: 0.005 to 0.050%, Cr: 0 to 0.25%, and V: 0 to 0.12%, with the balance being Fe and impurities. In the microstructure of a rim part of the railway wheel, an area fraction of pro-eutectoid cementite is 0.1 to 1.5% and an area fraction of pearlite is 95.0% or more.

MATERIAL FOR COLD ROLLED STAINLESS STEEL AND CONTAINER MADE THEREOF
20230065716 · 2023-03-02 ·

A material for cold rolled stainless steel has a chemical composition comprising: C: 0.08% or less, Si: 0.9% or less, Mn: 2% or less, P: 0.045% or less, S: 0.03% or less, Ni: 8% to 10.5%, Cr: 17.5% to 20%, Cu: 0.3% to 2.1%, and the balance of substantially Fe, wherein the cold rolled stainless steel has a tensile strength of 515 N/mm.sup.2 or more, a yield strength of 205 N/mm.sup.2 or more, and an elongation of 40% or more.