A method of manufacturing a pin (46) for a o mold (28) includes forming the pin (46) to include a substantially uniform initial hardness throughout the entire structure of the formed pin (46). The formed pin (46) is then processed with a hardening process, such that the processed pin(46) exhibits a hardness defining a hardness gradient that gradually increases from the initial hardness at a central interior region (56) of the pin (46) to an increased surface hardness at an exterior surface (60) of the pin (46). After processing the pin (46) with the hardening process, a coating (64) maybe deposited onto the exterior surface (60) of the pin (46) with a physical vapor deposition process. The coating (64) exhibits a hardness that is greater than the hardness of the increased surface hardness of the exterior surface (60) of the pin (46). The pin (46) may include, for example, a core pin, a squeeze pin, or an ejector pin.

A device for generating a microstructure with a structure gradient in an axisymmetric mechanical part having a hollow center and initially possessing a uniform structure with fine grains, the device including a first heater system defining a first shell for receiving the mechanical part and suitable for heating the outer periphery of the mechanical part to a first temperature higher than the solvus temperature. The device further includes a second heater system defining a second shell arranged inside the first shell and suitable for heating the inner periphery of the mechanical part to a second temperature lower than the solvus temperature, with the space between the first shell and the second shell defining a housing suitable for receiving the axisymmetric mechanical part having a hollow center.

The present disclosure relates to a method and a corresponding arrangement for producing a hardened sheet metal product. The method includes placing a sheet metal piece in a heating station and heating selected areas of the sheet metal piece in the heating station by means of induction. In this process, a coil induces currents that flow in a front metal layer on a front side of the coil. Opposing ends of the front metal layer are interconnected by a low resistance short-circuiting arrangement running on a rear side of the coil. The short-circuiting arrangement comprises a material with lower resistivity than the front metal layer. The heated piece is moved to a pressing station, where it is pressed while the heated areas are cooled.

An apparatus for manufacturing a rack bar includes a pre-forming machine forming a flattened portion on an outer peripheral surface of a hollow shaft member, a teeth forming machine forming rack teeth on the flattened portion, a heat treatment machine quenching the rack teeth, a first conveying machine carrying the shaft member into and from the pre-forming machine, a second conveying machine carrying the shaft member into and from the teeth forming machine, and a third conveying machine carrying the shaft member into and from the heat treatment machine. The first conveying machine, the second conveying machine, and the third conveying machine hold one end of the shaft member from a radially inner side of the shaft member. The apparatus of the rack bar are suitable for manufacturing a relatively short hollow rack bar having rack teeth formed over substantially an entire length of a shaft member.

A double row tapered roller bearing includes: an outer ring having an annular shape; an inner ring disposed on an inner circumferential side of the outer ring and having an annular shape; and rollers. The inner ring has an outer circumferential surface facing the outer ring and having two rows of grooves having a bottom surface serving as a raceway surface. The rollers are tapered rollers disposed in the grooves in contact with the raceway surface of the inner ring and are also in contact with the outer ring. At outer circumferential surface of the inner ring, a region adjacent to the groove includes a hardened region extending from the inner peripheral surface of the groove to the region adjacent to the groove, and an unhardened region located at a position farther from the groove than the hardened region and being smaller in hardness than the hardened region.

A method thermally treats hot rails to obtain a desired microstructure having enhanced mechanical properties. The method includes an active cooling phase where the rail is fast cooled from an austenite temperature and subsequently soft cooled, to maintain a target transformation temperature between defined values. The cooling treatment is performed by a plurality of cooling modules. Each of the cooling modules has a plurality of devices spraying a cooling medium onto the rail. The method is characterized in that during the active cooling phase, each cooling device is driven to control the cooling rate of the rail such that the amount of transformed austenite within the rail is not lower than 50% on the rail surface and not lower than 20% at a rail head core.

A steel sheet for hot pressing use according to the present invention has a specified chemical component composition, wherein some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, have an average equivalent circle diameter of 3 nm or more, the precipitated Ti amount and the total Ti amount in the steel fulfill the relationship represented by formula (1) shown below, and the sum total of the fraction of bainite and the fraction of martensite in the metal microstructure is 80 area % or more.

Precipitated Ti amount (mass %)3.4[N]>0.5[total Ti amount (mass %)3.4[N]](1)

(In the formula (1), [N] represents the content (mass %) of N in the steel.)

An apparatus for manufacturing a rack bar includes a pre-forming machine forming a flattened portion on an outer peripheral surface of a hollow shaft member, a teeth forming machine forming rack teeth on the flattened portion, a heat treatment machine quenching the rack teeth, a first conveying machine carrying the shaft member into and from the pre-forming machine, a second conveying machine carrying the shaft member into and from the teeth forming machine, and a third conveying machine carrying the shaft member into and from the heat treatment machine. The first conveying machine, the second conveying machine, and the third conveying machine hold one end of the shaft member from a radially inner side of the shaft member. The apparatus of the rack bar are suitable for manufacturing a relatively short hollow rack bar having rack teeth formed over substantially an entire length of a shaft member.

A laser surface treatment method for treating a surface of a workpiece having an irregular shape includes radiating a laser so that the surface of the workpiece which is placed in a direction forming an acute angle with respect to the laser becomes an untreated plane. The method also includes scanning with the laser so that the surface of the workpiece which is placed in the direction forming an acute angle with respect to the laser becomes an untreated plane.

System and method for induction hardening of metal rings, which includes two heads, each of which is attached to an induction medium; a system for vertical approximation of the two induction media to the metal ring; a system for horizontal approximation of the induction media to walls of an internal surface of the metal ring; and an oscillating circuit, wherein the system of vertical approximation displaces simultaneously in a vertical direction the two induction media until they are introduced into the metal ring; the system of horizontal approximation separates the two induction media from each other in a horizontal direction to bring each induction medium closer to the walls of the inner surface of the metal ring to heat it for a pre-established time, and to displace vertically the two induction media simultaneously until they reach a shower position to obtain the hardening of the metal ring.