Patent classifications
C21D8/0284
Graphene-coated steel sheet, and method for manufacturing same
A graphene-coated steel sheet and a method for manufacturing the same are provided. The graphene-coated steel sheet includes a steel sheet and a graphene layer formed on the steel sheet. Therefore, the graphene-coated steel sheet can be useful in preventing corrosion of iron, such as oxidation of iron, and has remarkably excellent thermal conductivity and electrical conductivity, as well as excellent heat resistance resulting from thermal stability of graphene. Also, the method can be useful in manufacturing a high-quality graphene-coated steel sheet having a monocrystalline form and showing substantially no defects or impurities.
STEEL FOIL FOR POWER STORAGE DEVICE CONTAINER, POWER STORAGE DEVICE CONTAINER, POWER STORAGE DEVICE, AND MANUFACTURING METHOD OF STEEL FOIL FOR POWER STORAGE DEVICE CONTAINER
A steel foil for a power storage device container includes a rolled steel foil, a nickel layer formed on a surface of the rolled steel foil, and a chromium-based surface treatment layer formed on a surface of the nickel layer. The nickel layer includes an upper layer portion which is in contact with the chromium-based surface treatment layer and contains Ni of 90 mass % or more among metal elements, and a lower layer portion which is in contact with the rolled steel foil and contains Ni of less than 90 mass % among the metal elements and Fe. <111> polar density in a reverse pole figure of the nickel layer in a rolling direction is 3.0 to 6.0. The nickel layer has a sub-boundary which is a boundary between two crystals having a relative orientation difference of 2 to 5, and a large angle boundary which is a boundary between two crystals having the relative orientation difference of equal to or more than 15. The average value of a ratio L5/L15 between a boundary length L5 which is the length of the sub-boundary, and a boundary length L15 which is the length of the large angle boundary, is equal to or more than 1.0.
Pre-diffused Al—Si coatings for use in rapid induction heating of press-hardened steel
A press-hardened steel component and a method of producing the same. In one form, a workpiece that will be formed into the component includes a coating that is pre-diffused with metal from the workpiece substrate. Examples of such protective coatings may include aluminum-based coatings, as well as from aluminum and silicon combinations. The pre-diffusion of the workpiece permits it to be subjected to the high heating rate of a subsequent press hardening operation without causing localized melting or vaporization of the protective coating.
STEEL PRODUCT FOR PROTECTING ELECTRICAL COMPONENTS FROM MECHANICAL DAMAGE
A steel product for protecting electrical components from mechanical damage and electrical short circuit resulting therefrom is disclosed. The steel product is produced from a lightweight steel comprising 6 to 30 wt % manganese, up to 12.0 wt % aluminum, up to 6.0 wt % silicon, 0.04 to 2.0 wt % carbon, and additionally one or more of the elements chromium, titanium, vanadium, niobium, boron, zirconium, molybdenum, nickel, copper, tungsten, cobalt at up to 5.0 wt % each and up to 10.0 wt % in total, the remainder iron, including common steel tramp elements, as hot-rolled strip or cold-rolled strip, sheet metal, or pipe, wherein the steel product is provided with an electrically non-conductive coating at least one side, on the side later facing the electrical components.
PROCESS FOR MANUFACTURING COLD-ROLLED STEEL SHEET
A hot-rolled steel sheet having a composition comprising, in mass %, C: 0.06 to 0.3%, Si: 0.4 to 2.5%, Mn: 0.6 to 3.5%, P: at most 0.1%, S: at most 0.05%, Ti: 0 to 0.08%, Nb: 0 to 0.04%, a total content of Ti and Nb: 0 to 0.10%, sol.Al: 0 to 2.0%, Cr: 0 to 1%, Mo: 0 to 0.3%, V: 0 to 0.3%, B: 0 to 0.005%, Ca: 0 to 0.003%, REM: 0 to 0.003%, the remainder Fe and impurities, is cold rolled, then heated at an average heating rate of at least 15 C./sec so that a proportion of an unrecrystallization of a region not transformed to austenite at a time of reaching (Ac.sub.1 point+10 C.) is at least 30 area %, and then held for 30 seconds at temperature of at least (0.9Ac.sub.1 point+0.1Ac.sub.3 point) and at most (Ac.sub.3 point+100 C.).
HIGH-STRENGTH HOT-DIP GALVANIZED STEEL SHEET AND PROCESS FOR PRODUCING THE SAME
A high-strength hot-dip galvanized steel sheet containing a main component, the steel sheet having at least 40 wt. % of ferrite as a main phase in terms of the volumetric ratio, and 8-60% inclusive of residual austenite, the remaining structure comprising one or more of bainite, martensite, or pearlite. Austenite particles within a range where the average residual stress (sigmaR) thereof satisfies the expression 400 MPa<=sigmaR<=200 MPa (formula (1)) are present in an amount of 50% or more in the hot-dip galvanized steel sheet. The surface of the steel sheet has a hot-dip galvanized layer containing less than 7 wt. % of Fe, the remainder comprising Zn, Al and inevitable impurities.
Hot-dip galvanized steel sheet for stamping having excellent cold workability, die hardenability, and surface quality, and producing method thereof
Disclosed is a hot-dip galvanized steel sheet for stamping, which has excellent cold workability, has such satisfactory surface quality as to be free from unplating and other defects even in the absence of dedicated facilities, and ensures a strength of 1370 MPa or more after quenching even when cooled at a low rate. Also disclosed is a method effective for the produce of the hot-dip galvanized steel sheet for stamping. The hot-dip galvanized steel sheet for stamping comprises a base steel sheet and a hot-dip galvanized layer on a surface of the base steel sheet, in which the base steel sheet has a predetermined chemical composition and has a microstructure comprising equiaxed ferrite having an average aspect ratio of 4.0 or less and cementite and/or pearlite having an average major axis of grains of 20 m or less.
High-strength steel sheet and method for producing the same
A high-strength steel sheet having a low yield ratio and a method for producing the same. The high-strength steel sheet has a specified chemical composition and a microstructure in which ferrite is present as a major phase, and martensite is present in an area fraction of 10% or greater and less than 50% relative to an entire area of the microstructure. The martensite has an average grain diameter of 3.0 m or less, in an entirety of the martensite, a proportion of martensite having an aspect ratio of 3 or less is 60% or greater, and the martensite having an aspect ratio of 3 or less has a carbon concentration of 0.30% or greater and 0.90% or less in mass %.
High Mn steel sheet for high corrosion resistance and method of manufacturing galvanizing the steel sheet
A high-manganese hot-dip coated steel sheet is disclosed which provides high corrosion resistance, high ductility and high strength, mainly used for inner and outer panels of automobiles, and a method of manufacturing the same. The high-manganese hot-dip coated steel sheet includes a substrate steel sheet having a composition of (in weight %) 0.1 to 1.5% of C, 5 to 35% of Mn, and the remainder includes Fe and other unavoidable impurities, and a hot-dip zinc coating layer formed on the substrate steel sheet, the hot-dip zinc coating layer having a composition of (in weight %) 0.1 to 10% of Mn, 5 to 15% of Fe, and the remainder including Zn and other unavoidable impurities.
Cold-rolled steel sheet with controlled microstructure, grain diameters, and texture
A high-strength cold-rolled steel sheet includes a composition having controlled amounts of carbon, silicon, manganese, phosphorous, sulfur, titanium, niobium, sol. Aluminum, chromium, molybdenum, vanadium, boron, calcium, REM, and iron. A microstructure thereof has a main phase of ferrite of at least 40 area %, and a second phase of a low-temperature transformation phase consisting either or both of martensite and bainite, which comprises at least 10 area % in total and retained austenite () at least comprising 3 area % . An average grain diameter of ferrite has a tilt angle of at least 15 is at most 5.0 mm, an average grain diameter of the low-temperature transformation-produced phase is at most 2.0 mm, an average grain diameter of lump-like retained having an aspect ratio of less than 5 is at most 1.5 mm, and an area fraction of the lump-like retained relative to the retained is at least 50%.