An orifice-type quenching nozzle for an induction hardening system includes a body having a plurality of nozzle orifices configured to apply a quenching fluid onto a to-be-quenched workpiece. The nozzle orifices are arranged on at least one surface of the body in rows and in columns, and the plurality of nozzle orifices are positioned such that each nozzle orifice is located a same distance from each directly adjacent nozzle orifice.

A method for controlling carbide network in a bearing steel wire rod by controlling cooling and rolling, comprises the following steps: rapidly rolling a bar to a wire rod and spinning it into a loose coil, controlling the rolling temperature at 780° C.-880° C.; and the spinning temperature at 750° C.-850° C.; carrying out on-line controlling cooling of continuous loose coils using EDC water bath austempering cooling process, controlling the cooling rate at 2.0° C./s-10° C./s, and controlling the final cooling temperature within 620-630° C.; after EDC water bath austempering cooling, using slow cooling under a cover, and the temperature is controlled to be 400° C.-500° C. when being removed out of the cover; after slow cooling, collecting coils, and cooling in air to the room temperature.

The invention relates to a method for the inductive surface layer hardening of a surface which runs around an annular component and has an initial zone, an end zone and two intermediate zones extending between the initial zone and the end zone. The initial zone is brought to hardening temperature by an inductor and quenched by a spray. Subsequently, an inductor arrangement is moved in each case along the intermediate zone to the end zone. Each inductor arrangement includes a leading inductor for preheating the region covered by it, a trailing inductor for finish-heating the preheated region and a spray for quenching the finish-heated region. After the inductor arrangements are located at a certain distance from the initial zone, the leading inductor of at least one of the inductor arrangements is moved in the direction of the end zone at an increased feed rate compared to the trailing inductor. The leading inductor thus reaches the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to overcome the distance previously resulted between said trailing inductor and the leading inductor. In the meantime, the end zone is preheated by the leading inductor that reached it. When one of the trailing inductors of the inductor arrangements has arrived in the end zone, it heats the end zone to the finished hardening temperature.

The invention provides a method for the inductive surface layer hardening of a surface running around an annular component of a hardenable steel, which achieves uniform and uninterrupted hardening. For this purpose, a) an initial zone of the surface is surface layer hardened by it being brought to hardening temperature by means of an inductor and being quenched with a spray. b) The surface is then hardened by means of a stationarily arranged inductor arrangement and a movably arranged inductor arrangement, which each comprise a leading inductor for preheating the region of the surface covered by it, a trailing inductor offset in the direction of the initial zone for finish-heating the pre-heated region to the hardening temperature and a spray for quenching the finish-heated region, wherein the movable inductor arrangement is moved along the surface and at the same time the annular component rotates about an axis of rotation in order to move the surface to be hardened along the stationary inductor arrangement. The speed of the movable inductor arrangement along the surface is greater than its circumferential speed. c) An end zone of the surface is then hardened by the leading inductor of one of the inductor arrangements being moved temporarily in the direction of the end zone at an increased feed rate compared to its trailing inductor when the end zone is located at a certain distance from inductor arrangements such that an enlarged distance results between the leading inductor and the inductor trailing it and the leading inductor is located at the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to cover the distance resulting between the trailing inductor and the leading inductor such that the at least one leading inductor arriving first at the end zone preheats the end zone until the trailing inductor is located at the end zone and finish-heats the end zone to hardening temperature. Finally, the finish-heated end zone is quenched by means of a spray.

The invention provides a method for the inductive surface layer hardening of a surface running around an annular component of a hardenable steel, which achieves uniform and uninterrupted hardening. For this purpose, a) an initial zone of the surface is surface layer hardened by it being brought to hardening temperature by means of an inductor and being quenched with a spray. b) The surface is then hardened by means of a stationarily arranged inductor arrangement and a movably arranged inductor arrangement, which each comprise a leading inductor for preheating the region of the surface covered by it, a trailing inductor offset in the direction of the initial zone for finish-heating the pre-heated region to the hardening temperature and a spray for quenching the finish-heated region, wherein the movable inductor arrangement is moved along the surface and at the same time the annular component rotates about an axis of rotation in order to move the surface to be hardened along the stationary inductor arrangement. The speed of the movable inductor arrangement along the surface is greater than its circumferential speed. c) An end zone of the surface is then hardened by the leading inductor of one of the inductor arrangements being moved temporarily in the direction of the end zone at an increased feed rate compared to its trailing inductor when the end zone is located at a certain distance from inductor arrangements such that an enlarged distance results between the leading inductor and the inductor trailing it and the leading inductor is located at the end zone by a time interval earlier, whose duration is equal to the duration required by the trailing inductor to cover the distance resulting between the trailing inductor and the leading inductor such that the at least one leading inductor arriving first at the end zone preheats the end zone until the trailing inductor is located at the end zone and finish-heats the end zone to hardening temperature. Finally, the finish-heated end zone is quenched by means of a spray.

A method for manufacturing a metal ring laminate includes: performing an aging treatment on a metal ring laminate in which a plurality of metal rings made of maraging steel are laminated; and performing a nitriding treatment on the metal ring laminate that has been nitrided. Oxidizing treatment is performed after the aging treatment but before the nitriding treatment at a temperature equal to or higher than 350° C. and lower than an aging treatment temperature.

A method for manufacturing a metal ring laminate includes: performing an aging treatment on a metal ring laminate in which a plurality of metal rings made of maraging steel are laminated; and performing a nitriding treatment on the metal ring laminate that has been nitrided. Oxidizing treatment is performed after the aging treatment but before the nitriding treatment at a temperature equal to or higher than 350° C. and lower than an aging treatment temperature.

A steel consists of, in mass %, C: 0.25 to 0.45%, Si: 0.10 to 0.50%, Mn: 0.40 to 0.70%, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%, Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfies Formula (1) to Formula (4) described in the present specification, wherein: its microstructure is composed of ferrite and pearlite having a total area fraction of 5.0 to 100.0%, and a hard phase having a total area fraction of 0 to 95.0%; a proportion of a total area of CaO—CaS—MgO—Al.sub.2O.sub.3 composite oxides with respect to a total area of oxides in the steel is 30.0% or more; and a number density of oxides having an equivalent circle diameter of 20.0 μm or more is 15.0 pieces/mm.sup.2 or less.

The invention relates to a method for producing a rolling bearing ring featuring an improved robustness against the formation of white etching cracks (WEC), wherein the rolling bearing component, which is made of a hypo-eutectoid heat-treated steel containing C in an amount of 0.4-0.55% and Cr in an amount of 0.5-2.0% in order to form a hardened boundary layer, is inductively heated, then quenched and subsequently tempered.

The invention relates to a method for producing a rolling bearing ring featuring an improved robustness against the formation of white etching cracks (WEC), wherein the rolling bearing component, which is made of a hypo-eutectoid heat-treated steel containing C in an amount of 0.4-0.55% and Cr in an amount of 0.5-2.0% in order to form a hardened boundary layer, is inductively heated, then quenched and subsequently tempered.