A bearing ring for a roller bearing includes: an inner layer part that is formed of tempering martensite or sorbite; and a surface layer part that surrounds the entire periphery of the inner layer part, in which Vickers hardness of a surface thereof is larger than that of the inner layer, and which is formed of tempering martensite. A raceway portion of the surface layer part a portion that is in contact with at least one end of the rolling contact surface of the roller in an axial direction, and includes a first raceway portion at which compressive residual stress of the raceway surface is relatively high.

In a thermal or thermochemical treatment, metal workpieces together with a metal guide are arranged on a batch carrier. The present invention relates to a device for flow guidance for metallic pieces during such thermal or thermochemical treatment and quenching, as well as methods using the same. The fluid guide particularly ensures a uniform cooling of an inner and/or outer lateral surface of the workpieces during the quenching process.

In a thermal or thermochemical treatment, metal workpieces together with a metal guide are arranged on a batch carrier. The present invention relates to a device for flow guidance for metallic pieces during such thermal or thermochemical treatment and quenching, as well as methods using the same. The fluid guide particularly ensures a uniform cooling of an inner and/or outer lateral surface of the workpieces during the quenching process.

A method of controlled cooling of one or multiple previously heated and substantially straight steel wire/wires of diameter more than 2.8 mm to a predetermined temperature range, comprises the steps: guiding the previously heated and substantially straight steel wire/wires along individual path/paths through one or multiple first coolant bath/baths comprising a bath liquid comprising water and a stabilizing additive. The bath liquid and the multiple previously heated and substantially straight steel wires create a steam film around each steel wire itself along each individual path; directing an impinging liquid immersed inside the first coolant bath/baths towards the previously heated and substantially straight steel wire/wires over a certain length L along individual path/paths, to cool down the previously heated and substantially straight steel wire/wires, the impinging liquid decreases the thickness of the steam film or destabilizes the steam film, thereby increasing the speed of cooling over the length L along individual path/paths; guiding the previously heated and substantially straight steel wire/wires along individual path/paths out of the first coolant bath/baths to be further cooled down in air; after the further cooling in air, guiding the previously heated, substantially straight steel wire/wires along individual path/paths through one or multiple second coolant bath/baths. In the method, the substantially straight steel wire/wires are subjected to a cooling transformation from austenite to pearlite.

A method of controlled cooling of one or multiple previously heated and substantially straight steel wire/wires of diameter more than 2.8 mm to a predetermined temperature range, comprises the steps: guiding the previously heated and substantially straight steel wire/wires along individual path/paths through one or multiple first coolant bath/baths comprising a bath liquid comprising water and a stabilizing additive. The bath liquid and the multiple previously heated and substantially straight steel wires create a steam film around each steel wire itself along each individual path; directing an impinging liquid immersed inside the first coolant bath/baths towards the previously heated and substantially straight steel wire/wires over a certain length L along individual path/paths, to cool down the previously heated and substantially straight steel wire/wires, the impinging liquid decreases the thickness of the steam film or destabilizes the steam film, thereby increasing the speed of cooling over the length L along individual path/paths; guiding the previously heated and substantially straight steel wire/wires along individual path/paths out of the first coolant bath/baths to be further cooled down in air; after the further cooling in air, guiding the previously heated, substantially straight steel wire/wires along individual path/paths through one or multiple second coolant bath/baths. In the method, the substantially straight steel wire/wires are subjected to a cooling transformation from austenite to pearlite.

A method of continuous controlled cooling of a plurality of heated steel wires having a diameter larger than 2.8 mm and having an austenite microstructure and of transformation to a pearlite microstructure of the steel wires. The method comprises the steps of: a) Providing a first coolant bath comprising a first coolant liquid. The first coolant liquid comprises water and a stabilizing additive. b) Guiding the plurality of previously heated steel wires parallel to each other along individual paths through the first coolant liquid contained in the first coolant bath; and directing impinging liquid immersed inside the first coolant bath towards each of the steel wires over a certain length L. The impinging liquid decreases the thickness of or destabilizes the steam film around each of the plurality of steel wires, resulting in an increase of the speed of cooling over said length L. The intensity of the impinging liquids is individually set and/or controlled for each individual steel wire or for subsets of the plurality of steel wires. c) Guiding the plurality of steel wires parallel to each other through air for further cooling.

A method of continuous controlled cooling of a plurality of heated steel wires having a diameter larger than 2.8 mm and having an austenite microstructure and of transformation to a pearlite microstructure of the steel wires. The method comprises the steps of: a) Providing a first coolant bath comprising a first coolant liquid. The first coolant liquid comprises water and a stabilizing additive. b) Guiding the plurality of previously heated steel wires parallel to each other along individual paths through the first coolant liquid contained in the first coolant bath; and directing impinging liquid immersed inside the first coolant bath towards each of the steel wires over a certain length L. The impinging liquid decreases the thickness of or destabilizes the steam film around each of the plurality of steel wires, resulting in an increase of the speed of cooling over said length L. The intensity of the impinging liquids is individually set and/or controlled for each individual steel wire or for subsets of the plurality of steel wires. c) Guiding the plurality of steel wires parallel to each other through air for further cooling.

A method of and an equipment for controlled cooling of one or multiple previously heated, straight, and thick steel wire to a predetermined temperature range between 400 C. and 650 C. Each of the thick steel wires is subjected to a controlled cooling-transformation treatment from austenite to pearlite, which occurs substantially after the wire leaves a forced water cooling length.

A method of and an equipment for controlled cooling of one or multiple previously heated, straight, and thick steel wire to a predetermined temperature range between 400 C. and 650 C. Each of the thick steel wires is subjected to a controlled cooling-transformation treatment from austenite to pearlite, which occurs substantially after the wire leaves a forced water cooling length.

A circulation apparatus recovers cooling fluid after the cooling fluid is used for quenching and supplies the cooling fluid to a defoaming bath. A laminar flow weir of a defoaming apparatus partitions the defoaming bath into laminar and shallow flow baths. The laminar flow weir is lower than a side wall of the laminar flow bath. Cooling fluid from the circulation apparatus is supplied to the laminar flow bath and the cooling fluid is poured into the shallow bath from the laminar flow bath along the laminar flow weir. A filter covers an opening in a bottom portion of the shallow bath. The liquid level height in the shallow bath is less than the height of the laminar flow weir. A supply bath accumulates cooling fluid that passes through the filter, and supplies the cooling fluid to a cooling apparatus that sprays the cooling fluid onto a metallic material.