Abstract: According to one aspect of the present invention, there is provided a process of fabricating a steel material by performing a heat treatment to a steel material having high strength, in order to reduce hardness at one part of the steel material to less than hardness at other parts of the steel material, wherein the heat treatment comprises a heating step in which a portion having a certain depth from a surface of the steel material is rapidly heated by induction heating or direct energization heating, and a cooling step in which the steel material, which has been subject to the heating step, is rapidly cooled a predetermined time after the heating step, and a heating temperature in the heating step is Ac1 transforming point or more.

Abstract: An induction hardening monitoring apparatus (20) comprising: a current sensor (21) for detecting output current from a high-frequency inverter (11); a voltage sensor for detecting a voltage generated in a heating coil (14) connected between output terminals of the high-frequency inverters (11) together with a capacitor (12) in an equivalent circuit manner; and a controller (23) for monitoring a hardening processing based on a detection signal from the current sensor (21) and a detection signal from a voltage sensor (22), wherein the controller (23) monitors a hardening processing by calculating an effective value of output current from the high-frequency inverter (11) based on a detection signal from the current sensor (21) and calculating an effective value of voltage generated in a heating coil (14) based on a detection signal from the voltage sensor (22); or further calculating load impedance based on each effective value.

Abstract: A hardening apparatus (10), comprising a heating zone (20) induction heating coiled members (12) to a hardening temperature and cooling zone (30) rapidly cooling the coiled members (12) induction heated to the hardening temperature. A carrying route (22) for carrying the coiled members (12) in the direction of arrow A (carrying direction) while the coiled members are rotating and an induction heating coil (24) for induction heating the coiled members (12) being carried on the carrying route (22) while the coiled members are rotating are disposed in the heating zone (20). The large number of coiled members (12) are placed on the carrying route (22) at specified intervals so that the longitudinal direction thereof crosses the carrying direction and carried continuously.

Abstract: A heat treatment apparatus 10 comprises a supporting unit 20 for supporting a columnar workpiece 12 turnably, and an induction-heating coil 30 for induction-heating the workpiece 12 supported turnably by the supporting unit 20. Below the workpiece 12 supported by the supporting unit 20, a cooling tank 50 is provided which contains a liquid coolant. The workpiece 12 is made of steel such as carbon steel for mechanical structure, and spring steel. The workpiece 12 is made of a material which has a magnetic transformation point at 770° C. The material is ferromagnetic below this temperature, and becomes paramagnetic above this temperature.

Abstract: A non-evaporation getter material suitable for non-evaporation getters disposed in electron devices, such as fluorescent luminous tubes. The getter material is sized and shaped to more efficiently absorb gases actively at low temperatures.

Abstract: A heat treatment apparatus 10 comprises a supporting unit 20 for supporting a columnar workpiece 12 turnably, and an induction-heating coil 30 for induction-heating the workpiece 12 supported turnably by the supporting unit 20. Below the workpiece 12 supported by the supporting unit 20, a cooling tank 50 is provided which contains a liquid coolant. The workpiece 12 is made of steel such as carbon steel for mechanical structure, and spring steel. The workpiece 12 is made of a material which has a magnetic transformation point at 770° C. The material is ferromagnetic below this temperature, and becomes paramagnetic above this temperature.

Abstract: In an induction heating coil for heating a shaft member having multiple steps, annular conductors are separately disposed in the axis direction, the annular conductors having inner diameters so as to form predetermined gaps with outer peripheries of heating portions of the shaft member, the lengths of annular conductors (1, 2, and 3) are set so that the areas of the respective heating portions are approximately equal to each other, and the annular conductors are connected to each other in series, so that the respective step shaft portions of the shaft member are uniformly heated. The annular conductors described above may be formed to have shapes in conformity with the shapes of the heating portions of the shaft member and may be formed to have a step shape corresponding to steps of the shaft member having different outer diameters.

Abstract: The one end side portion is nipped by a jig including a jig member having a pair of convex portions which are to be fitted to a depressions in contact with a tooth side face and a inclined portion and positioning a bar and a jig member which is to be clamped/opened with respect to the jig member. A die having an inside diameter smaller than the diameter of the outer periphery is pressed onto the outer periphery of the end portion of the cylindrical end side portion projected from the jig up to a press-in depth determined preliminarily based on the rack, so as to reduce the diameter of the end portion.

Abstract: With a first push rod which is to be inserted/removed into/from a steel pipe through an opening at one end and a second push rod which is to be inserted/removed into/from the steel pipe through an opening at the other end, a metal core disposed on a side on which the first push rod is inserted/removed into/from the die assembly is sandwiched and this metal core is stopped from rotating with the first push rod. With the state of stopping the rotation of the first push rod, the metal core is introduced into the steel pipe through the opening at the one end by both the push rods. After the metal core is pressed into the steel pipe while stopped from rotating with the first push rod, this metal core is pushed back by the second push rod.

Abstract: A converter (311) converts an AC electric power (e) to the DC electric power with a DC voltage value corresponding to a setting. An inverter (312) is controlled by a frequency electric power control circuit (330) to convert the DC electric power to a dual frequency AC electric power for alternately outputting low and high frequencies at a frequency ratio (duty) corresponding to the setting. A matching transformer (321) having a tap (321C) at which the resonance impedance corresponds to the output impedance of a generator (310) receives the dual frequency AC electric power. A low-frequency series resonance circuit (325) or a high-frequency series resonance circuit (326) is caused to provide a series resonance, thereby causing an induction heating coil (200) to induction heat a workpiece-to-be-heated (201). In this way, the single generator (310) and the single induction heating coil (200) are used to effectively induction heat the workpiece-to-be-heated (201) by means of the dual frequency resonance.

Abstract: Ultradispersed ones of primary particles of nanometer-sized carbon are obtained by applying a wet-type milling method and/or a wet dispersion method to an aggregate structure of the primary particles to overcome van der Waals forces, by which forces the primary particles are held together to form the aggregate structure, whereby the ultradispersed primary particles are obtained in a colloidal dispersion on a large-scale basis at low cost without using any additive. In a method of manufacturing the ultradispersed primary particles, the wet-type milling method is carried out in a ball mill, preferably in combination with a high-energy ultrasonic-wave process carried out in a dispersing medium such as pure water, whereby a colloidal solution or slurry with a low-concentration of the primary particles ultradispersed in the dispersing medium is obtained.

Abstract: A hardening apparatus (10), comprising a heating zone (20) induction heating coiled members (12) to a hardening temperature and cooling zone (30) rapidly cooling the coiled members (12) induction heated to the hardening temperature. A carrying route (22) for carrying the coiled members (12) in the direction of arrow A (carrying direction) while the coiled members are rotating and an induction heating coil (24) for induction heating the coiled members (12) being carried on the carrying route (22) while the coiled members are rotating are disposed in the heating zone (20). The large number of coiled members (12) are placed on the carrying route (22) at specified intervals so that the longitudinal direction thereof crosses the carrying direction and carried continuously.

Abstract: A heat treatment apparatus 10 comprises a supporting unit 20 for supporting a columnar workpiece 12 turnably, and an induction-heating coil 30 for induction-heating the workpiece 12 supported turnably by the supporting unit 20. Below the workpiece 12 supported by the supporting unit 20, a cooling tank 50 is provided which contains a liquid coolant. The workpiece 12 is made of steel such as carbon steel for mechanical structure, and spring steel. The workpiece 12 is made of a material which has a magnetic transformation point at 770° C. The material is ferromagnetic below this temperature, and becomes paramagnetic above this temperature.

Abstract: In a coil spring of closed-end type, the coil spring is characterized in that a coupler is fixedly mounted between: an outer peripheral surface of a terminal convolution of a coil element rod; and, an outer peripheral surface of a subsequent convolution subsequent to the terminal convolution of the coil spring of closed-end type, whereby an amount of initial deflection is decreased.

Abstract: In an induction heating coil for heating a shaft member having multiple steps, annular conductors are separately disposed in the axis direction, the annular conductors having inner diameters so as to form predetermined gaps with outer peripheries of heating portions of the shaft member, the lengths of annular conductors 1, 2, and 3 are set so that the areas of the respective heating portions are approximately equal to each other, and the annular conductors are connected to each other in series, so that the respective step shaft portions of the shaft member are uniformly heated. The annular conductors described above may be formed to have shapes in conformity with the shapes of the heating portions of the shaft member and may be formed to have a step shape corresponding to steps of the shaft member having different outer diameters.

Abstract: A converter (311) converts an AC electric power (e) to the DC electric power with a DC voltage value corresponding to a setting. An inverter (312) is controlled by a frequency electric power control circuit (330) to convert the DC electric power to a dual frequency AC electric power for alternately outputting low and high frequencies at a frequency ratio (duty) corresponding to the setting. A matching transformer (321) having a tap (321C) at which the resonance impedance corresponds to the output impedance of a generator (310) receives the dual frequency AC electric power. A low-frequency series resonance circuit (325) or a high-frequency series resonance circuit (326) is caused to provide a series resonance, thereby causing an induction heating coil (200) to induction heat a workpiece-to-be-heated (201). In this way, the single generator (310) and the single induction heating coil (200) are used to effectively induction heat the workpiece-to-be-heated (201) by means of the dual frequency resonance.

Abstract: A spacer 44 is inserted between an upper end face 44a of a contact column 40, and a lower face of a flange 14. The flange 14 is supported at plural positions by supporting columns 42. In heating a shoulder portion 16 to a hardening temperature, an electroconductive member 56 is placed close to the shoulder portion 16, and an AC current having a frequency which will cause mutual attraction between the current flowing through the elctroconductive member 56 and the current flowing through the shoulder portion 16 is applied to flow through the electroconductive member 56. The shoulder portion 16 having been heated to the hardening temperature is quenched by ejecting a liquid coolant through ejection outlets of a cooling jacket.

Abstract: A liquid phase diffusion bonding method for dissimilar metal sheets by allowing a galvanized steel sheet and an aluminum alloy sheet to come into close contact with each other and pressing both sheets by using a first mold of a liquid phase diffusion bonding apparatus and a second mold of the same; and heating the sheets at approximately the same heat-up rate and at approximately the same temperature to perform liquid phase diffusion bonding of the sheets by using induction heat generated by applying high frequency currents to a first high frequency induction heating coil provided on the first mold and a second high frequency induction heating coil provided on the second mold. The first high frequency induction heating coil and the second high frequency induction heating coil are positioned to sandwich the sheets at predetermined distances from the sheets, respectively.

Abstract: A double tapered steel wire (S) is evenly heat treated over the entire length thereof. The wire (S) has its constant-diameter straight portion (21, 24) disposed between its opposite end tapered portions (22, 23) each tapered down to its reduced-diameter outer end. In heat treatments, a diameter of the wire (S) is continuously detected by a detection means (3, 6), so that the amount of energy of induction heating applied to the wire (S) is controlled by a control unit (12) in a manner such that the amount of the energy is proportional to a wire diameter of the wire (S) having been detected, whereby heat applied to the wire (S) varies over the entire length of the wire (S). As a result, the wire (S) is quenched and tempered over its entire length in a manner such that the wire (S) thus heat treated has its small-diameter portions (24) and its large-diameter portion (21) differ from each other in tensile strength.

Abstract: Described is a steering rack bar which is low in costs, which is hollowed in overall length, and for use in steering equipment for automobiles. A rack is formed on a first steel tube by plastic working, wherein the first steel tube has good plastic workability by low carbon content, and has high strength after hardening. The above first steel tube and a second steel tube are joined to complete a hollow steering rack bar, wherein the second steel tube has a higher carbon content and is lower in cost than the first steel tube. Moreover, the second steel tube which has a margin of the strength can be thinner than the first steel tube for reduction of weight.