Abstract: An induction heating method for a metal strip is provided to heat a continuously conveyed metal strip using an induction heating device disposed at a first position on a pass line. The induction heating method includes a step of detecting a displacement from a predetermined datum line of a width direction center line of the metal strip at a second position on the pass line that is different from the first position, a step of computing an estimated displacement of the width direction center line of the metal strip at the first position by temporal and spatial extrapolation of the displacement based on a function expressing a time series of changes in the displacement, and a step of controlling a relative positional relationship between the induction heating device and the metal strip in a width direction of the metal strip based on the estimated displacement.

Abstract: An electric resistance welded pipe welding device for manufacturing an electric resistance welded pipe that melts both end face portions, of an open pipe having an opening portion extending in a running direction, both the end face portions that face the opening portion each other from both sides and are made of a pipe material, by induced currents generated by an induction heating means and brings the end face portions into contact with each other at a squeeze roll unit while gradually narrowing a gap of the opening portion and welds the end face portions together, the electric resistance welded pipe welding device includes: as the induction heating means, an induction coil composed of a pair of opening-vicinity conductor parts that are extended in the running direction along the end face portions at both sides of the opening portion and are arranged apart from an outer peripheral surface of the open pipe at positions not overlapping the opening portion in a plan view; and a first-portion circulating conduct

Abstract: An induction heating device for a metal strip includes a first induction coil member and a second induction coil member provided in parallel with a metal strip across the metal strip that travels in a longitudinal direction, provided to protrude from the metal strip, and provided so as not to overlap each other in the traveling direction of the metal strip, and a magnetic core member provided between the first induction coil member and the second induction coil member, and provided to cover a large area of an end portion in the sheet width direction of the metal strip on the side of each of the first induction coil member and the second induction coil member, and cover a small area of the end at a center portion between the first induction coil member and the second induction coil member.

Abstract: An induction heating device for a metal strip, including: an induction coil provided on one side or on both sides of a front face side or a reverse face side of a metal strip, and that induces an induction current in the strip when a primary current is passed through the coil, the induction current configuring a closed loop as viewed from a direction perpendicular to a metal strip face; plural magnetic cores disposed at a specific position, this being a position at a back face side of the coil and separated from the strip by a specific distance, to concentrate magnetic flux generated by the coil in the strip; and a moving mechanism coupled to the magnetic cores, and that moves the cores to increase or decrease a disposed number of the cores at the specific position disposed side-by-side along a metal strip width direction.

Abstract: In the electric-resistance-welded pipe welding apparatus, after a metal strip that is traveling is bent into a cylindrical shape by rolls so that both ends in a width direction of the metal strip face each other, a power supply portion of an induction heating device or an energization heating device is provided immediately near the metal strip which is bent into the cylindrical shape, a joule heating is performed with respect to the both ends by a power supplied from the power supply portion, thereafter, and the both ends are welded while being pressed to and coming in contact with each other. The electric-resistance-welded pipe welding apparatus includes a ferromagnetic body that is movably inserted between the both ends at a position further to the upstream than the power supply portion when viewed along the traveling direction of the metal strip, the position corresponding to an opening portion between the both ends which face each other.

Abstract: An apparatus for manufacturing electric resistance welded pipe, in which two across-opening-facing end parts (2a, 2b) of an open pipe (1) including an opening (2) extending in a running direction are melted by an induction current generated by an induction heating means and joined together at a join portion. The induction heating means includes a first induction coil (3), and the first induction coil (3) is disposed above the opening (2) so as not to encircle the outer circumference of the open pipe (1) and so that a primary current circuit is formed straddling the opening (2).

Abstract: An induction heating apparatus for heating a traveling metal plate includes an induction coil for surrounding the metal plate. The induction coil includes an upper portion for being located above the metal plate and a lower portion for being located below the metal plate. The upper and lower portions of the induction coil are spaced from each other in a longitudinal direction of the metal plate at least at one position in a transverse direction of the metal plate. The distance in the longitudinal direction of the metal plate between the upper portion and the lower portion of the induction coil varies across a transverse direction of the metal plate.

Abstract: An induction heating device for a metal strip includes a first induction coil member and a second induction coil member provided in parallel with a metal strip across the metal strip that travels in a longitudinal direction, provided to protrude from the metal strip, and provided so as not to overlap each other in the traveling direction of the metal strip, and a magnetic core member provided between the first induction coil member and the second induction coil member, and provided to cover a large area of an end portion in the sheet width direction of the metal strip on the side of each of the first induction coil member and the second induction coil member, and cover a small area of the end at a center portion between the first induction coil member and the second induction coil member.

Abstract: An induction heating device for a metal strip, including: an induction coil provided on one side or on both sides of a front face side or a reverse face side of a metal strip, and that induces an induction current in the strip when a primary current is passed through the coil, the induction current configuring a closed loop as viewed from a direction perpendicular to a metal strip face; plural magnetic cores disposed at a specific position, this being a position at a back face side of the coil and separated from the strip by a specific distance, to concentrate magnetic flux generated by the coil in the strip; and a moving mechanism coupled to the magnetic cores, and that moves the cores to increase or decrease a disposed number of the cores at the specific position disposed side-by-side along a metal strip width direction.

Abstract: A quenched steel pipe member is formed of a GI galvanized steel pipe, in a middle section in a longitudinal direction of the GI galvanized steel pipe, a cross-section perpendicular to the longitudinal direction has a substantially V shape including a contact section at which opposite parts of an inner circumferential surface of the GI galvanized steel pipe come into contact with each other, the contact section is bonded using a Fe—Zn alloy phase, and a micro Vickers hardness at a location 50 ?m deep from a base material surface layer is 95% or more of a micro Vickers hardness at a location 200 ?m deep from the base material surface layer.

Abstract: An electric-resistance-welded pipe welding apparatus includes: an impeder that is disposed in the inner portion of a metal strip which is bent into the cylindrical shape, and is disposed spanning over from the upstream to the downstream of a position in which the induction coil is present when viewed along a traveling direction of the metal strip; and a metallic shield plate that is disposed further upstream than an upstream end of the impeder and is disposed in a position which is further downstream than the rolls when viewed along the traveling direction, the metallic shield plate including a hole portion through which the metal strip bent into the cylindrical shape passes, and the metallic shield plate shielding a magnetic flux generated in the induction coil.

Abstract: An apparatus for manufacturing electric resistance welded pipe, in which two across-opening-facing end parts (2a, 2b) of an open pipe (1) including an opening (2) extending in a running direction are melted by an induction current generated by an induction heating means and joined together at a join portion. The induction heating means includes a first induction coil (3), and the first induction coil (3) is disposed above the opening (2) so as not to encircle the outer circumference of the open pipe (1) and so that a primary current circuit is formed straddling the opening (2).

Abstract: A quenched steel pipe member is formed of a GI galvanized steel pipe, in a middle section in a longitudinal direction of the GI galvanized steel pipe, a cross-section perpendicular to the longitudinal direction has a substantially V shape including a contact section at which opposite parts of an inner circumferential surface of the GI galvanized steel pipe come into contact with each other, the contact section is bonded using a Fe—Zn alloy phase, and a micro Vickers hardness at a location 50 ?m deep from a base material surface layer is 95% or more of a micro Vickers hardness at a location 200 ?m deep from the base material surface layer.

Abstract: An induction heating apparatus for controlling the temperature distribution for heating a metal plate irrespective if it has a small thickness, is magnetic or nonmagnetic, and capable of coping with a change in the width of the plate, or meandering of the plate.

Abstract: An induction heating apparatus for heating a traveling metal plate includes an induction coil for surrounding the metal plate. The induction coil includes an upper induction coil for being located above the metal plate and a lower induction coil for being located below the metal plate. The upper and lower induction coils are spaced from each other in a longitudinal direction of the metal plate a constant distance across a transverse direction of the metal plate. Each of the upper induction coil and the lower induction coil is arranged obliquely at an edge area of the metal plate so as to form an oblique angle with the transverse direction of the metal plate.

Abstract: The invention provides an induction heating system and method of using it for heating a metal plate. The induction coil of the induction heating system includes sections each having conductors at front and back surfaces of the metal plate, which are arranged such that at least a one of the front or back surface conductor has a part slanted in the width direction of the metal plate, and vertical projections of the conductors onto the metal plate do not overlap at the center of the metal plate but overlap outside the edges of the metal plate. In addition, front conductors from adjacent sections are spaced differently as back conductors. The induction heating system allows for better control of the heating temperature distribution regardless of the metal plates thickness and magnetic properties, especially temperature distributions at the edges of the metal plate.

Abstract: An electric-resistance-welded pipe welding apparatus includes: an impeder that is disposed in the inner portion of a metal strip which is bent into the cylindrical shape, and is disposed spanning over from the upstream to the downstream of a position in which the induction coil is present when viewed along a traveling direction of the metal strip; and a metallic shield plate that is disposed further upstream than an upstream end of the impeder and is disposed in a position which is further downstream than the rolls when viewed along the traveling direction, the metallic shield plate including a hole portion through which the metal strip bent into the cylindrical shape passes, and the metallic shield plate shielding a magnetic flux generated in the induction coil.

Abstract: In the electric-resistance-welded pipe welding apparatus, after a metal strip that is traveling is bent into a cylindrical shape by rolls so that both ends in a width direction of the metal strip face each other, a power supply portion of an induction heating device or an energization heating device is provided immediately near the metal strip which is bent into the cylindrical shape, a joule heating is performed with respect to the both ends by a power supplied from the power supply portion, thereafter, and the both ends are welded while being pressed to and coming in contact with each other. The electric-resistance-welded pipe welding apparatus includes a ferromagnetic body that is movably inserted between the both ends at a position further to the upstream than the power supply portion when viewed along the traveling direction of the metal strip, the position corresponding to an opening portion between the both ends which face each other.

Abstract: An induction heating apparatus for heating a traveling metal plate includes an induction coil for surrounding the metal plate. The induction coil includes an upper portion for being located above the metal plate and a lower portion for being located below the metal plate. The upper and lower portions of the induction coil are spaced from each other in a longitudinal direction of the metal plate at least at one position in a transverse direction of the metal plate. The distance in the longitudinal direction of the metal plate between the upper portion and the lower portion of the induction coil varies across a transverse direction of the metal plate.

Abstract: A system for induction heating a metal plate passing through an inside of an induction coil, which induction heating system arranging at least two sections of the induction coil adjacent in a longitudinal direction of said metal plate, wherein when vertically projecting the induction coil of the front surface side and back surface side of said metal plate onto said metal plate, said front surface side and back surface side conductors are arranged offset so as not to overlap in the longitudinal direction of said metal plate in that vertical projection, further, said front surface side conductors being in proximity and said back surface side conductors being arranged having a distance apart more or said back surface side conductors being in proximity and said front surface side conductors being arranged having a distance apart more, said induction heating system able to control the heating temperature distribution even for thin metal plate without regard to being magnetic or nonmagnetic, in particular an induct