Neturen Co., Ltd.

National Institute for Materials Science

Fumiaki Ikuta

Kazuhiro Kawasaki

Hironori Ooyama

Takahiko Kanai

Kotobu Nagai

Yutaka Kiyosawa

Takashi Horino

Tetsuya Ono

Yue Yang

Masao Hayakawa

Munehisa Hatta

Takehiko Itagaki

Takashi Ikeda

Masato Sugimoto

Kunihiro Kobayashi

Akira Terajima

Kazutomi Oka

Kazuki Mori

Tsuyoshi Yoshida

Toshihiro Aiba

Taichi Kitamura

Eizaburo Nakanishi

Yoshitaka Kuwahara

Yoshimasa Tanaka

Hiroki Inoue

Keisuke Ito

Yoshitaka Misaka

Hidehiro Yasutake

Eizaburou Nakanishi

Shinichi Takase

Kengo Fukazawa

Masayuki Miyake

Mitsuhiro Okamoto

Masayuki Komatsu

Tokio Sekigawa

Tetsukazu Hukuhara

Gorou Atsuta

Takeshi Yoshikawa

Jun Fujie

Takeshi Endoh

Yasuyuki Koyata

Ken-ichi Hoshiba

Ken-Ichi Hoshiba

An induction heating system includes induction heating apparatuses, each including a high-frequency current transformer, a low-frequency current transformer and a heating coil, a high-frequency input switch connected to the high-frequency current transformer, a low-frequency input switch connected to the low-frequency current transformer, a first power source to output a high-frequency electric power and a low frequency electric power, a second power source, a first power source output switch connectable to the first power source, a second power source output switch connectable to the second power source, and a switch controller. Each induction heating apparatus includes a heater controller to send a signal to the switching controller to turn on one of the first power source output switch and the second power source output switch, to turn off the other, and to switch on or off each of the high-frequency input switch and the low-frequency input switch.

Induction heating system, induction heating method, output monitoring apparatus, output monitoring method, and induction heating apparatus

A direct resistance heating apparatus includes first and second electrodes arranged with a space provided therebetween, a power supply electrically connected to the electrodes, an electrode moving mechanism configured to move, in a state in which the electrodes are in contact with a workpiece and in a state in which current is applied from the power supply to the workpiece through the electrodes, at least one of the electrodes along an opposing direction in which the electrodes are opposed to each other, first and second holders configured to hold the workpiece such that, in a state in which the at least one of the electrodes is moved, a heating target region of the workpiece located between the electrodes is held between the holders in the opposing direction, and a holder moving mechanism configured to move at least one of the holders to pull the workpiece along the opposing direction.

Direct resistance heating apparatus, direct resistance heating method, heating apparatus, heating method, and hot-press molding method

A method for setting conditions for a shaft diameter enlargement, a shaft diameter enlargement method, and a shaft diameter enlargement apparatus are provided. A controller of the shaft diameter enlargement apparatus controls a compressing section, a bending section, and a rotating section to enlarge an intermediate portion of a shaft workpiece to have a predetermined outer diameter by rotating the shaft workpiece about its axis with axial compressive force a bending angle being applied to the intermediate portion. The controller determines whether the shaft workpiece is acceptable, based on the number of rotations of die shaft workpiece required for enlarging the intermediate portion to have the predetermined outer diameter or based on an enlargement ratio of the intermediate portion.

Shaft diameter enlargement condition setting method, shaft diameter enlargement method and shaft diameter enlargement apparatus

A direct resistance heating simulation method is provided. In this method, a welding region and its peripheral region of steel sheets to be welded by a pair of electrodes are divided into a plurality of elements. A coupled analysis is performed such that a temperature, a metal structure, stress and strain at each element are determine in a mutually associated manner based on Joule loss obtained through a current analysis and a magnetic field analysis for each element. The coupled analysis is repeated to predict an effect of one or more parameters, including at least one of a frequency, a magnitude and an application time of electric current to be applied to the electrodes, a cooling time, a pressure applied from the electrodes to the steel sheets and a shape of the electrodes, on welding quality after a post-heating by direct resistance heating and to improve weld strength.

Direct resistance heating simulation method

A method and an apparatus for manufacturing a stepped member are provided. An intermediate portion of a shaft workpiece is radially enlarged while being compressed in an axial direction by applying alternating load to the intermediate portion in a direction intersecting the axial direction in a state in which pressure that compresses the shaft workpiece in the axial direction is applied to both ends of the shaft workpiece. The enlarged intermediate portion of the shaft workpiece is cat in a direction perpendicular to the axial direction so that the shaft workpiece is divided into two stepped members. Each of the stepped members has a shaft portion and a head portion provided at an axial end of the shaft portion, and the head portion has a larger diameter than the shaft portion.

Method and apparatus for manufacturing stepped member

A heating method, a heating apparatus, and a method of manufacturing a press-molded article using the heating method are provided. A pair of electrodes is arranged on a workpiece along a first direction. Each electrode has a length extending across a first heating area of the workpiece in the first direction. At least one of the electrodes is moved in the first heating area and along a second direction intersecting the first direction at a constant speed while applying electric current between the pair of electrodes to heat the first heating area by direct resistance heating. The electric current applied between the pair of electrodes is adjusted such that a heating temperature is adjusted for each segment into which the first heating area is divided so as to be side by side in the second direction.

Heating method, heating apparatus and method of manufacturing press-molded article

A heating method, a heating apparatus, and a method for manufacturing a press-molded article using the heating method are provided. Electrodes are placed on a workplace to extend across a heating target region in a first direction. At least one of the electrodes is moved in a second direction perpendicular to the first direction over the heating target region while applying electric current to the electrodes. A distribution of contact pressure between at least one of the electrodes and the workpiece along the first direction is adjusted, with a plurality of segment regions being defined by dividing the heating target region such that the segment regions are arranged side by side in the first direction, and in accordance with a length of each of the segment regions between the electrodes, to adjust a healing temperature of each of the segment regions of the heating target region.

Heating method, heating apparatus and method for manufacturing press-molded article

A wire heating system includes an induction heating apparatus having a power supply and an induction coil arranged to heat a wire rod by an induction heating using current supplied from the power supply, and a controller configured to control the current to be supplied to the induction coil based on a feeding speed of the wire rod. The induction heating apparatus has a heating section in which the wire rod is heated by the induction heating using the induction coil, and a soaking section located downstream of the heating section to homogenize the temperature distribution of the induction-heated wire rod. The controller is configured to control the current to be supplied to the induction coil such that a temperature of the wire rod at a downstream end of the soaking section becomes a target temperature.

Wire heating system and wire heating method

Object of the present invention is to provide a welding method prevented the fracture at the spot welding zone by recovering the strength of a spot welding zone, namely, the ductility and the toughness in the spot welding zone, and a weld structure manufactured by the method. In the welding method, a spot welding zone provided with a weld nuggetis formed by conducting spot welding on the heat treated steel sheets in a stack; the spot welding zone is tempering treated by the high-frequency electrical current application to make the weld nugget have a hardness of 150% or less of the hardness of the heat treated steel sheets, and the heat affected zone surrounding the weld nugget is made to have a hardness of 30% to 90% of the hardness at the weld nugget before the tempering treatment by the high-frequency electrical current application.

Welding method and weld structure

An induction heating coil () has a primary coil () to which electric power is supplied and a ring-shaped secondary coil () forming a closed circuit. The primary coil () has a base-side portion that covers an outer periphery of the secondary coil () and a distal-side portion extending from the base-side portion in the center axis direction of the secondary coil () in a state in which the base-side portion covers the secondary coil (). The opening width of the base-side portion is greater than the opening width of the distal-side portion. The secondary coil () is provided such that it can be inserted into and removed from the inside of the primary coil () from the base-side portion of the primary coil ().

Induction heating coil, induction heating device, and heating method

In a direct resistance heating method, a current is applied to a plate workpiece having a varying cross-sectional area to heat the workpiece such that a high-temperature heating region and a non-high-temperature heating region are provided side by side. The method includes a preparation step of arranging a pair of electrodes on the workpiece, and a heating step of moving a first electrode from one end of the high-temperature heating region while applying a current to the pair of electrodes, stopping the movement of the first electrode when the first electrode reaches the other end of the high-temperature heating region, and stopping the current from being applied to the pair of electrodes when a predetermined time elapses after stopping the first electrode. A press-molded product manufacturing method includes pressing the workpiece that has been heated by direct resistance heating method using a press die to perform hot press molding.

Direct resistance heating method and press-molded product manufacturing method

A welding equipment for metallic materials capable of performing heat treatment such as tempering based on partial heating in spot welding is provided. The welding equipment sandwiches metallic materials with a pair of electrodes, and heats different regions of the metallic materials by energization, with the pair of electrodes maintained at the same position with respect to the metallic materials. The welding equipment includes a first heating means connected to the pair of electrodes for heating and welding the internal region of the circle defined by projecting the cross-sectional area of the axis of the electrodes on the metallic materials by applying power having a low first frequency, a second heating means for heating a ring-shaped region along the circle by applying power having a second frequency that is higher than the first frequency, and an energization control unit for independently controlling the first and the second heating means.

Welding equipment for metallic materials and method for welding metallic materials

An induction apparatus including a hardening control unit for controlling an induction hardening apparatus based on setup conditions data; a hardening monitoring unit that measures, as measurement data, the electric quantity in an electric circuit and that monitors an induction hardening status; and a data collecting unit that collects the data from various sensors in the induction hardening apparatus obtained when the induction hardening apparatus subjects the work to an induction hardening based on the setup conditions data outputted from the hardening control unit and that collects the measurement data from the hardening monitoring unit to store the collected data from the various sensors and the measurement data so that the collected data are associated to each other.

Induction hardening control system

A welding structural partis manufactured by overlapping the surfaces of steel sheets, and forming a weld zone by spot welding. The weld zoneincludes: a weld nugget; and a heat affected zonesurrounding the weld nugget, wherein the hardness in the weld zone increases along an exterior regionof the heat affected zonetoward the heat affected zone, and then decreases along the heat affected zonetoward the central region of the weld nugget. In the boundary region between the weld nuggetand the heat affected zone, the weld nuggetmay have a convex portionA bulging into the heat affected zonealong the overlapped portion. The steel sheetscontain carbon in 0.15 mass % or more.

Welding structural part and welding method of the same

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Tokyo, Japan

Fumiaki Ikuta