C21D9/00

Multi-step aging process for improved bond durability

A method of treating an aluminum material to increase adhesive bond durability is disclosed. The disclosed method includes a first aging step of heating an aluminum component to a first temperature no more than 150° C. (302° F.) for a first time period followed by a second aging step including heating the aluminum component to a second temperature greater than the first temperature for a second time period.

STEEL SHEET FOR HOT STAMPING
20220170128 · 2022-06-02 · ·

A steel sheet for hot stamping includes: a steel sheet having a predetermined chemical composition; and a plating layer provided on a surface of the steel sheet, the plating layer having an adhesion amount of 10 g/m.sup.2 to 90 g/m.sup.2 and a Ni content of 10 mass % to 25 mass %, and containing a remainder consisting of Zn and impurities. The steel sheet for hot stamping includes, in a surface layer region of the steel sheet, 80% or more by area % of grains having an average crystal orientation difference of 0.4° to 3.0° inside grains surrounded by grain boundaries having an average crystal orientation difference of 5° or more.

MAGNETIC RIBBON AND MAGNETIC CORE USING SAME

A magnetic ribbon according to an embodiment has a crystallinity degree of 0.05 or higher and 0.4 or lower when the magnetic ribbon is subjected to XRD analysis, the magnetic ribbon being Fe—Nb—Cu—Si—B-base, and the crystallinity degree being expressed by “a peak total area of a crystalline phase”/(“a peak area of an amorphous phase”+“the peak total area of the crystalline phase”). Also, the magnetic ribbon is preferred to have a region in which a KIKUCHI pattern is detected when the crystalline phase is subjected to EBSD analysis. Also, the thickness of the magnetic ribbon is preferred to be 25 μm or less.

STRIP FLOTATION FURNACE

A strip flotation furnace for controlling the temperature of a metal strip has a flotation nozzle bar extending through the furnace transversely to a strip running direction of the strip. The flotation nozzle bar has two opposing first flotation nozzle rows spaced apart by a central region of the flotation nozzle bar. The rows are set up so that corresponding flotation nozzle jets, with a directional component toward the central region, can be generated to provide pressure cushioning for metal strip guiding. A temperature-control nozzle bar extends transversely to and is spaced apart from the flotation nozzle bar along the strip running direction. The temperature-control nozzle bar has two additional opposing temperature-control nozzle rows spaced apart by an additional temperature-control nozzle bar central region. These rows are set up so that corresponding temperature-control nozzle jets, with a directional component opposite to the additional central region, can be generated.

HOT-WORKING DIE STEEL, HEAT TREATMENT METHOD THEREOF AND HOT-WORKING DIE

The present invention relates to a hot-working die steel, a heat treatment method thereof and a hot-working die. Specifically, the present invention discloses a hot-working die steel, its alloying composition comprises, by weight percentage, Cu: 2˜8%, Ni: 0.8˜6%, and Ni:Cu≥0.4, C: 0˜0.2%, Mo: 0˜3%, W: 0˜3%, Nb: 0˜0.2%, Mn: 0˜0.8%, Cr: 0˜1%, the balance of Fe and other alloying elements and impurities. The present invention also discloses a heat treatment method for performing on the hot-working die steel. The present invention further discloses a hot-working die formed of the hot-working die steel underwent through heat treatment according to the heat treatment method.

SURFACE-MODIFYING METHOD FOR STEEL MATERIAL AND STEEL STRUCTURE

Provided are an effective and simple surface-modifying method for prolonging the life of a steel structure made of a steel material having a high sulfur (S) content, and a steel structure having a life prolonged by the surface-modifying method. A surface-modifying method for forming a friction stir region on the surface of a steel material by friction stir processing, wherein a sulfur (S) content of the steel material is 200 ppm or more.

PRE-HARDENED STEEL COMPOSITION AND MACHINE PARTS MADE THEREWITH

A mud pump with components manufactured from high strength and toughness steel is disclosed. The mud pump includes a power end and a fluid end. The power end includes a motor, crankshaft rotationally engaged with the motor and a connecting rod rotationally engaged with the crank shaft. The fluid end includes a piston, a cylinder, a drilling fluid module, a discharge manifold, and a strainer cross. At least one of the plunger, the drilling fluid module, the discharge manifold, and the strainer cross has the following composition in weight percent: 0.25-0.55% carbon, 0.70-1.50% manganese, a maximum of 0.025% phosphorous, a maximum of 0.050% sulfur, a maximum of 0.80% silicon, 0.10-0.80% nickel, 1.40-2.20% chromium, 0.10-0.55% molybdenum, a maximum of 0.030% vanadium, a maximum of 0.35% copper, a maximum of 0.040% aluminum, a balance of iron, and incidental impurities.

Low-cost and high-formability 1180 MPa grade cold-rolled annealed dual-phase steel plate and manufacturing method thereof

A low-cost and high-formability 1180 MPa grade cold-rolled annealed dual-phase steel plate and a manufacturing method thereof are provided. The dual-phase steel plate has the following chemical composition by mass percentages: C: 0.1%-0.125%, Si: 0.4%-0.8%, Mn: 2.6%-2.9%, Al: 0.01%-0.05%, Nb: 0.01%-0.03%, and Ti: 0.01%-0.03%, the remainder being Fe and unavoidable impurities. By reasonable design of alloy elements and manufacturing processes, the dual-phase steel plate of the invention achieves a strength of 1180 MPa grade at a low cost, obtains a fine and uniform martensite-ferrite dual-phase structure that ensures excellent elongation rate and cold bending performance, and has good formability. The dual-phase steel plate has a yield strength of more than 850 MPa, a tensile strength of more than 1180 MPa, an elongation rate of 8% or more, and a parameter (R/t), characterizing the 90-degree cold bending performance, of 2.5 or less.

Hot-stamped body

There is provided a hot-stamped body including: a steel base metal; and a metallic layer formed on a surface of the steel base metal, wherein the metallic layer includes: an interface layer that contains, in mass %, Al: 30.0 to 36.0%, has a thickness of 100 nm to 5 μm, and is located in an interface between the metallic layer and the steel base metal; and a principal layer that includes coexisting MgZn.sub.2 phases and insular FeAl.sub.2 phases, is located on the interface layer, and has a thickness of 3 μm to 40 μm.

Ferritic stainless steel having excellent high-temperature oxidation resistance, and manufacturing method therefor
11339460 · 2022-05-24 · ·

Disclosed are a ferritic stainless steel capable of inhibiting high temperature oxidation through generation of an effective oxide scale, and manufacturing method thereof. The ferritic stainless steel excellent in oxidation resistance at high temperature according to an embodiment of the present disclosure includes, in percent (%) by weight of the entire composition, Cr: 10 to 30%, Si: 0.2 to 1.0%, Mn: 0.1 to 2.0%, W: 0.3 to 2.5%, Ti: 0.001 to 0.15%, Al: 0.001 to 0.1%, the remainder of iron (Fe) and other inevitable impurities, and satisfies a following equation (1).
W/(Ti+Al)≥10  (1)