A heat treatment apparatus for hot stamping includes a frame, and heating units provided to be vertically movable at both upper and lower sides of the frame and configured to heat a cold formed steel plate by electrifying the steel plate. Cooling units are provided to be vertically movable at centers of the upper and lower sides of the frame and are configured to cool the heated steel plate while pressurizing the steel plate from upper and lower sides.

To bond bonding target members stacked on top of each other without generating dust or spatter into an electrically bonded article with improved mechanical strength against strong vibration etc. A first bonding target member or second bonding target member includes a relative displacement amount setting portion for setting the distance by which the bonding target portion of the first member and the bonding target portion of the second member are relatively displaced during bonding, and a current conduction suppressing layer is formed on the relative displacement amount setting portion. The second or first member includes a setting face that is placed opposed to the current conduction suppressing layer of the first or second member. In a state where the first and second members have been positioned, the distance between the current conduction suppressing layer and the setting face is equal to the width H of the bonded portion.

To bond bonding target members stacked on top of each other without generating dust or spatter into an electrically bonded article with improved mechanical strength against strong vibration etc. A first bonding target member or second bonding target member includes a relative displacement amount setting portion for setting the distance by which the bonding target portion of the first member and the bonding target portion of the second member are relatively displaced during bonding, and a current conduction suppressing layer is formed on the relative displacement amount setting portion. The second or first member includes a setting face that is placed opposed to the current conduction suppressing layer of the first or second member. In a state where the first and second members have been positioned, the distance between the current conduction suppressing layer and the setting face is equal to the width H of the bonded portion.

Processes for forming blanks having tailored properties in localized areas are provided. The blanks are then formed into three-dimensionally shaped components (e.g., high-strength automotive parts). A sheet of high-strength metal alloy may be selectively heated in a first region to a temperature below a melting point of the metal alloy with a heat source, while a second region of the sheet adjacent to the first region remains unheated. The selective heating creates a first region of the metal alloy having at least one material property distinct from the second region. After the sheet is cut to form a blank, the blank comprises a portion of the first region and a portion of the second region. In this manner, a plurality of distinct tailored regions may be formed on each blank. The process may be continuous or semi-continuous and further include cutting of blanks from the sheet. High-strength structural components are also provided.

Processes for forming blanks having tailored properties in localized areas are provided. The blanks are then formed into three-dimensionally shaped components (e.g., high-strength automotive parts). A sheet of high-strength metal alloy may be selectively heated in a first region to a temperature below a melting point of the metal alloy with a heat source, while a second region of the sheet adjacent to the first region remains unheated. The selective heating creates a first region of the metal alloy having at least one material property distinct from the second region. After the sheet is cut to form a blank, the blank comprises a portion of the first region and a portion of the second region. In this manner, a plurality of distinct tailored regions may be formed on each blank. The process may be continuous or semi-continuous and further include cutting of blanks from the sheet. High-strength structural components are also provided.

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically forming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool are provided. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous material and the equilibrium melting point of the alloy in a time scale of several milliseconds or less. Once the sample is uniformly heated such that the entire sample block has a sufficiently low process viscosity it may be shaped into high quality amorphous bulk articles via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, and blow molding in a time frame of Less than 1 second.

An apparatus and method of uniformly heating, rheologically softening, and thermoplastically forming metallic glasses rapidly into a net shape using a rapid capacitor discharge forming (RCDF) tool are provided. The RCDF method utilizes the discharge of electrical energy stored in a capacitor to uniformly and rapidly heat a sample or charge of metallic glass alloy to a predetermined “process temperature” between the glass transition temperature of the amorphous material and the equilibrium melting point of the alloy in a time scale of several milliseconds or less. Once the sample is uniformly heated such that the entire sample block has a sufficiently low process viscosity it may be shaped into high quality amorphous bulk articles via any number of techniques including, for example, injection molding, dynamic forging, stamp forging, and blow molding in a time frame of Less than 1 second.

Provided is a hot-band annealing method comprising subjecting a Si-containing hot rolled steel sheet, having an oxidized scale formed on a surface of the steel sheet by hot rolling, to hot-band annealing with a hot-band annealing equipment provided with a heating zone, a soaking zone, a cooling zone, and a rapid heating device at an upstream side of the heating zone and/or in an inlet side of the heating zone, wherein the hot rolled steel sheet is heated by not lower than 50° C. at a heating rate of not less than 15° C./s by using the rapid heating device to improve a descaling property. Also, provided is a descaling method characterized by subjecting the Si-containing hot rolled steel sheet, after the hot-band annealing, to descaling only by pickling without requiring mechanical descaling or heating the steel sheet in the pickling process.

A method for producing a nitrided packaging steel from a hot-rolled steel product with a carbon content of 400 to 1200 ppm, utilizing a cold-rolling of the steel product to a flat steel product, subsequent recrystallization annealing of the cold-rolled flat steel product in an annealing furnace, in particular a continuous annealing furnace. A nitrogen-containing gas is supplied into the annealing furnace and is directed at the flat steel product to introduce unbonded nitrogen into the flat steel product in an amount corresponding to a concentration of more than 100 ppm, or to increase the amount of unbonded nitrogen in the flat steel product to a concentration of more than 100 ppm, and subsequent cooling of the recrystallized annealed flat steel product at a cooling rate of at least 100 K/s directly after the recrystallization annealing. Using this method, cold-rolled flat steel products may be produced for packaging purposes with a tensile strength of more than 650 MPa and in particular between 700 and 850 MPa.

A method for producing a nitrided packaging steel from a hot-rolled steel product with a carbon content of 400 to 1200 ppm, utilizing a cold-rolling of the steel product to a flat steel product, subsequent recrystallization annealing of the cold-rolled flat steel product in an annealing furnace, in particular a continuous annealing furnace. A nitrogen-containing gas is supplied into the annealing furnace and is directed at the flat steel product to introduce unbonded nitrogen into the flat steel product in an amount corresponding to a concentration of more than 100 ppm, or to increase the amount of unbonded nitrogen in the flat steel product to a concentration of more than 100 ppm, and subsequent cooling of the recrystallized annealed flat steel product at a cooling rate of at least 100 K/s directly after the recrystallization annealing. Using this method, cold-rolled flat steel products may be produced for packaging purposes with a tensile strength of more than 650 MPa and in particular between 700 and 850 MPa.