A method is for producing a three-dimensional vehicle door frame inner reinforcement element (52) including an inner center pillar part (66), an inner front pillar part (68) and an inner side rail part (64) joining the inner center pillar part (66) and the inner front pillar part (68). The method includes providing an inner center pillar blank, an inner front pillar blank and an inner side rail blank, said inner blanks being substantially planar, assembling the inner center pillar blank and the inner front pillar blank to the inner side rail blank in order to form a substantially planar door frame inner reinforcement blank, and hot stamping the door frame inner reinforcement blank to shape the three-dimensional door frame inner reinforcement element (52).

A method of manufacturing a hot-stamped part includes: inserting a blank into a heating furnace including a plurality of sections with different temperature ranges; step heating the blank in multiple stages; and soaking the blank at a temperature of about Ac3 to about 1,000° C., wherein in the step of heating the blank, a temperature condition in the heating furnace satisfies the following equation: 0<(Tg−Ti)/Lt<0.025° C./mm, where Tg denotes a soaking temperature (° C.), Ti denotes an initial temperature (° C.) of the heating furnace, and Lt denotes a length (mm) of step heating sections.

A cooling method for a workpiece includes placing entirety of the workpiece in an inner space of a recess provided on a molding surface of a lower mold, pressing or restraining the workpiece by a mold including the lower mold and an upper mold in which a protrusion corresponding to the recess of the lower mold is provided on a molding surface, supplying a liquid coolant to the inner space of the recess through a coolant supply passage provided in at least one of the lower mold and the upper mold by a pump, and discharging air in the inner space of the recess upward through an air escape passage, and cooling the workpiece by immersing the entirety of the workpiece, which has been heated, in the liquid coolant that fills the recess.

A tailor-welded blank is made of two steels, one steel of Alloy A and one steel of Alloy B. Alloy A comprises 0.10-0.50 wt % C, 0.1-0.5 wt % Si, 2.0-8.0 wt % Mn, 0.0-6.0 wt % Cr, 0.0-2.0 wt % Mo, 0.0-0.15 wt % Ti, and 0.0-0.005 wt % B and wherein Alloy B comprises 0.06-0.12 wt % C, 0.1-0.25 wt % Si, 1.65-2.42 wt % Mn, 0.0-0.70 wt % Cr, 0.08-0.40 wt % Mo, 0.0-0.05 wt % V, and 0.01-0.05 wt % Ti.

A method of forming a shaped steel object, includes cutting a blank from an alloy composition. The alloy composition includes 0.1-1 wt. % carbon, 0.1-3 wt. % manganese, 0.1-3 wt. % silicon, 1-10 wt. % aluminum, and a balance being iron. The method also includes heating the blank to a temperature above a temperature at which austenite begins to form to generate a heated blank, transferring the heated blank to a die, forming the heated blank into a predetermined shape defined by the die to generate a shaped steel object, and decreasing the temperature of the shaped steel object to ambient temperature. The heating is performed under an atmosphere comprising at least one of an inert gas, a carbon (C)-based gas, and nitrogen (N.sub.2) gas.

A method of forming a shaped steel object is provided. The method includes cutting a blank from an alloy composition including 0.05-0.5 wt. % carbon, 4-12 wt. % manganese, 1-8 wt. % aluminum, 0-0.4 wt. % vanadium, and a remainder balance of iron. The method also includes heating the blank until the blank is austenitized to form a heated blank, transferring the heated blank to a press, forming the heating blank into a predetermined shape to form a stamped object, and decreasing the temperature of the stamped object to a temperature between a martensite start (Ms) temperature of the alloy composition and a martensite final (Mf) temperature of the alloy composition to form a shaped steel object comprising martensite and retained austenite.

The invention provides a component formed of an aluminum alloy for use in a vehicle, for example an automotive vehicle component requiring high strength, light-weight, and a complex three-dimensional shape, and a method of manufacturing the component. The method begins by providing a blank formed of an aluminum alloy which is already solution heat treated and tempered, and thus has a temper designation of about T4. The method further includes heating the blank to a temperature of 150° C. to 350° C., preferably 190° C. to 225° C. The method next includes quickly transferring the blank to a hot or warm forming apparatus, and stamping the blank to form the complex three-dimensional shape. Immediately after the forming step, the component has a temper designation of about T6, but preferably not greater than T6, and thus is ready for use in the vehicle without any post heat treatment or machining.

A hot stamped body comprising a steel base material and an Al—Zn—Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 90.0% of an Mg—Zn containing phase, 5.0 to less than 30.0% of an Fe—Al containing phase, and 2.0 to 25.0% of an Al—Si containing oxide phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg.sub.2 Zn.sub.3 phase, and MgZn.sub.2 phase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase.

This steel sheet for hot stamping includes a base material, an Al-Si alloy plating layer in which the Al content is 75 mass% or more, the Si content is 3 mass% or more and the total of the Al content and the Si content is 95 mass% or more and a Ni plating layer in which the Ni content is more than 90 mass% in this order, the chemical composition of the base material is, by mass%, C: 0.01% or more and less than 0.70%, Si: 0.005% to 1.000%, Mn: 0.40% to 3.00%, Nb: 0.010% to 0.200%, a solid solution of Nb: 0.010% to 0.150%, sol. A1: 0.00020% to 0.50000%, P: 0.100% or less, S: 0.1000% or less, N: 0.0100% or less, Cu: 0% to 1.00%, Ni: 0% to 1.00%, V: 0% to 1.00%, Ti: 0% to 0.150%, Mo: 0% to 1.000%, Cr: 0% to 1.000%, B: 0% to 0.0100%, Ca: 0% to 0.010%. REM: 0% to 0.300%, and a remainder: Fe and an impurity, the Al-Si alloy plating layer has a thickness of 7 to 148 .Math.m, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.

A method for forming a component to a target shape from an aluminium blank workpiece is disclosed, the method comprising: (a) cold forming an aluminium blank workpiece between a set of dies, thereby producing a component fully or partially formed to a target shape; (b) solution heat treating the fully or partially formed component by heating to or above a solution heat treatment (SHT) temperature and substantially maintaining that temperature until SHT has been completed, thereby producing a solution heat treated fully or partially formed component; and (c) quenching the solution heat treated fully or partially formed component whilst held between a set of dies, wherein holding between the dies may provide additional forming at the same time as quenching, to produce a component fully formed to the target shape.