C21D9/00

Heat treatment method and heat treatment apparatus
11230746 · 2022-01-25 · ·

The invention relates to a method and an apparatus for the targeted heat treatment of specific component zones of a steel component. A predominantly austenitic structure can be created in the steel component in one or more first regions, from which, by quenching, a majority martensitic microstructure can be created; and in one or more second regions, a majority bainitic microstructure can be created, wherein the steel component is initially heated in a furnace to a temperature above the AC3 temperature, the steel component is subsequently transferred into a treatment station, and can cool down during the transfer, and in the treatment station, the one or more second regions of the steel component are cooled down to a cooling finish temperature ϑ.sub.2 during a treatment time.

Method of fabrication of composite material based on vanadium alloy and steel

The method of producing composite material with a high complex of mechanical properties, consisting of vanadium alloy inner layer V—3-11 wt % Ti—3-6 wt % Cr and two outer layers of stainless steel of ferritic grade with chromium content of not less than 13 wt %, includes preparation of a composite workpiece consisting of said inner layer and outer layers, hot treatment by pressure and subsequent exposure in furnace. Prepared composite workpiece, thickness of inner layer of which is 1.5-2 times more than total thickness of outer layers of stainless steel, hot working is performed with pressure of the workpiece in the temperature range of 1,050-1,150° C. with degree of reduction from 30 to 40% and with subsequent exposure for 1-3 hours with temperature reduction to 500-700° C., then annealing workpiece by heating to temperature of 850-950° C., holding for 2-4 hours and subsequent cooling in furnace.

LOCALIZED RESISTANCE ANNEALING PROCESS
20220017982 · 2022-01-20 ·

A localized annealing process and a part having localized areas with increased ductility produced by the process. The part is formed of hard material, tempered, and/or otherwise hardened such that it meets minimum hardness and ductility requirements. The part further includes localized areas that have increased ductility for workability, which could include various types of deformation. The localized annealing process includes providing a part with low levels of ductility and then annealing localized areas of the part for increased ductility that will need to be machined or attached to another formed part. The annealing process includes placing an electrode on either side of the localized area and generating electricity through the localized area. The material in the localized area is then heated from the electricity to form a more ductile physical structure.

STEEL SHEET FOR CANS AND METHOD FOR MANUFACTURING THE SAME

A steel sheet for cans has a chemical composition containing, in mass percent, C: 0.085% to 0.130%, Si: 0.04% or less, Mn: 0.10% to 0.60%, P: 0.02% or less, S: more than 0.010% to 0.020%, Al: 0.02% to 0.10%, N: 0.0005% to 0.0040%, Nb: 0.007% to 0.030%, and B: 0.0010% to 0.0050%, B/N that is the ratio of the content (mass percent) of B to the content (mass percent) of N being 0.80 or more, the remainder being Fe and inevitable impurities, and a ferrite microstructure containing 1.0% or more pearlite in terms of area fraction. The steel sheet for cans has a yield stress of 500 MPa or more, a tensile strength of 550 MPa or more, a uniform elongation of 10% or more, and a yield elongation of 5.0% or less.

Hot stamped article

A hot stamped article of high strength steel sheet excellent in bending deformability having a predetermined chemical composition, having an area rate of 90% or more of the microstructures of the steel sheet comprised of one or more of lower bainite, martensite, and tempered martensite, and having a ratio of the length of grain boundaries with a rotational angle about a rotational axis of the <011> direction of the crystal grains of the lower bainite, martensite, and tempered martensite of 15° or more with respect to the length of grain boundaries with a rotational angle of 5° to 75° of 80% or more.

Hot-work die steel and a preparation method thereof

The present application provides a hot-work die steel and a preparation method thereof wherein the chemical constituents of the hot-work die steel in mass percentage are as follows: C: 0.20-0.32 wt %, Si: ≤0.5 wt %, Mn: ≤0.5 wt %, Cr: 1.5-2.8 wt %, Mo: 1.5-2.5 wt %, W: 0.5-1.2 wt %, Ni: 0.5-1.6 wt %, V: 0.15-0.7 wt %, Nb: 0.01-0.1 wt %, and a balance of iron, wherein an alloying degree is 5-7%; a tensile strength of the hot-work die steel at 700° C. is 560-700 MPa; a value of hardness of the hot-work die steel at room temperature is 32-38 HRC after holding at 700° C. for 3-5 h; and the hot-work die steel has an elongation of 14% to 16% at room temperature, a percentage reduction of area of 48% to 65%, and an impact toughness of 52-63 J at room temperature. The hot-work die steel of the present application has an excellent thermal stability as well as a good plasticity and a toughness at room temperature.

Apparatus for loading/unloading workpieces into/from furnace

An apparatus for loading/unloading workpieces, including a furnace heating a workpiece, and a robot loading and/or unloading a workpiece into/from the furnace. The robot may include a manipulator linkage and a fork at an end of the manipulator linkage. The fork may have an upper side on which a workpiece is placed while being loaded into and/or unloaded from the furnace. The fork may include a parallel arrangement of fork elements, each fork element in the fork having a length and rectangular cross section perpendicular to the length. Each fork element may have a workpiece carrying surface on which a workpiece is placed and an opposite surface to the workpiece carrying surface. The fork element may include a heat insulator disposed on the workpiece carrying surface at least over an area where a workpiece is placed to equalize longitudinal thermal expansions in the workpiece carrying surface and the opposite surface.

SCALLOP-RESISTANT TRACK LINK AND METHOD OF MAKING SAME
20220009569 · 2022-01-13 · ·

A track link includes an elongate link body formed of a link body material that varies in hardness to form a first lower hardness zone, a second lower hardness zone, and a higher hardness zone. The higher hardness zone includes an upper rail surface of the elongate link body and extends substantially throughout the elongate link body outside of the first and second lower hardness zones, which surround the track pin bores. Related methodology for making a track link is also disclosed.

ROUGHLY-SHAPED STEEL MATERIAL FOR NITRIDED PART, AND NITRIDED PART
20220010416 · 2022-01-13 ·

Provided are a roughly-shaped steel material for a nitrided part, and a nitrided part obtained by nitriding the roughly-shaped steel material for a nitrided part, having a determined chemical composition, in which the portion with a diameter or width ranging from 60 to 130 mm of the roughly-shaped steel material for a nitrided part has a microstructure at a depth of 14.5 mm from a surface including, in terms of area fraction: tempered martensite and tempered bainite in total: from 70 to 100%; remaining austenite: from 0 to 5%; and a balance: ferrite and perlite; and has a microstructure at a depth of 15 mm or more from the surface including, in terms of area fraction: tempered martensite and tempered bainite in total: from 0 to less than 50%; remaining austenite: from 0 to 5%; and a balance: ferrite and perlite.

Heat-treatment apparatus and heat-treatment method

A heat-treatment apparatus includes a casing, a loader which loads a workpiece to an inner part of the casing in order to apply a heat-treatment to the workpiece, and a canopy surface provided in the casing to cover the workpiece. The canopy surface includes a slope way with a sectional configuration where the canopy surface is cut on a plane vertical to a conveying direction of the workpiece inside the casing. The slope way includes a highest point and a downward inclined surface extending from the highest point to an outside of a zone between a perpendicular line extending from a left end of the workpiece and a perpendicular line extending from a right end of the workpiece.