A forming device includes a fluid supply unit that is disposed at an end portion of a metal pipe material and supplies a first fluid to an inside of the metal pipe material via an opening of the end portion, in which the fluid supply unit includes a surrounding portion that surrounds an outer peripheral surface of the end portion and at which an annular groove portion is formed on an inner peripheral surface facing the outer peripheral surface, an annular sealing member disposed in the groove portion, and an operating portion at which a pressurizing force that pressurizes the sealing member toward the outer peripheral surface is generated.

A forming device includes a fluid supply unit that is disposed at an end portion of a metal pipe material and supplies a first fluid to an inside of the metal pipe material via an opening of the end portion, in which the fluid supply unit includes a surrounding portion that surrounds an outer peripheral surface of the end portion and at which an annular groove portion is formed on an inner peripheral surface facing the outer peripheral surface, an annular sealing member disposed in the groove portion, and an operating portion at which a pressurizing force that pressurizes the sealing member toward the outer peripheral surface is generated.

A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes first and second dies paired with each other and including pipe forming surfaces for forming the pipe portion and flange forming surfaces for forming the flange portion, a drive unit that drives at least one of the first and second dies, and a controller that controls the drive unit, in which, on at least one of the flange forming surfaces of the first and second dies, a protrusion portion protruding by an amount not to abut against the other flange forming surface when the dies are closed is formed and the controller controls the drive unit to form a thin wall portion at which a thickness of the flange portion becomes partially small at the flange portion by the protrusion portion pressing the flange portion.

A forming device which expands a metal pipe material to form a metal pipe having a pipe portion and a flange portion includes first and second dies paired with each other and including pipe forming surfaces for forming the pipe portion and flange forming surfaces for forming the flange portion, a drive unit that drives at least one of the first and second dies, and a controller that controls the drive unit, in which, on at least one of the flange forming surfaces of the first and second dies, a protrusion portion protruding by an amount not to abut against the other flange forming surface when the dies are closed is formed and the controller controls the drive unit to form a thin wall portion at which a thickness of the flange portion becomes partially small at the flange portion by the protrusion portion pressing the flange portion.

A forming apparatus which forms a metal pipe by expanding a metal pipe material, includes: a forming die for forming the metal pipe; a first electrode and a second electrode which clamp the metal pipe material at both end sides and heat the metal pipe material by causing an electric current to flow through the metal pipe material; and a first fluid supply unit and a second fluid supply unit which supply a fluid into the metal pipe material heated by the first electrode and the second electrode to expand the metal pipe material, wherein at least one of the first electrode and the second electrode is provided with a movement restriction mechanism which restricts a movement of the metal pipe material in an axial direction of the metal pipe material.

A metal pipe having an outer diameter of 150 mm to 3,000 mm and a wall thickness of 2 mm to 50 mm, and a method for manufacturing the same. The method includes a pipe-end-portion expansion step of expanding pipe end portions that are located at both ends of a mother pipe and an internal pressure application step that is performed after the pipe-end-portion expansion step and in which the mother pipe is expanded by applying an internal pressure, p, to the entire interior of the mother pipe until the internal pressure, p (MPa), that corresponds to changes in an axial compression amount s (mm), the axial compression amount, s, representing an amount of compression in a pipe axial direction against pipe extreme ends which are the both ends of the mother pipe, becomes a preset maximum internal pressure pmax (MPa), and p and s satisfy a specified formula.

A metal pipe having an outer diameter of 150 mm to 3,000 mm and a wall thickness of 2 mm to 50 mm, and a method for manufacturing the same. The method includes a pipe-end-portion expansion step of expanding pipe end portions that are located at both ends of a mother pipe and an internal pressure application step that is performed after the pipe-end-portion expansion step and in which the mother pipe is expanded by applying an internal pressure, p, to the entire interior of the mother pipe until the internal pressure, p (MPa), that corresponds to changes in an axial compression amount s (mm), the axial compression amount, s, representing an amount of compression in a pipe axial direction against pipe extreme ends which are the both ends of the mother pipe, becomes a preset maximum internal pressure pmax (MPa), and p and s satisfy a specified formula.

A method for shaping a blank comprising a metal includes a step of loading the blank onto a first die, a step of bringing the first die and a second die together, a step of forming a seal around the blank, and a step of injecting a pressurized molten salt into a space in the blank to supply a hydraulic pressure to the blank.

A method for shaping a blank comprising a metal includes a step of loading the blank onto a first die, a step of bringing the first die and a second die together, a step of forming a seal around the blank, and a step of injecting a pressurized molten salt into a space in the blank to supply a hydraulic pressure to the blank.

An expansion forming apparatus that shapes a metal material with a die includes an electrode that comes into contact with the metal material and performs energization heating, and an electrode mounting unit having an electrode movement actuator that moves the electrode along an extension direction of the metal material during heating.