The method includes: the step of preparing a steel material and a work portion; the step of placing the steel material on the work portion; and the steps of obtaining the rolling bearing ring by heating the steel material on the work portion to a temperature equal to or higher than an A.sub.1 transformation point, thereafter punching a part of the steel material into a ring shape, and thereafter quenching the steel material in a ring shape on the work portion. In the step of obtaining the rolling bearing ring, heating and punching are performed in the state where oxidation of the steel material is suppressed, and in the state where tensile force is applied between the first portion and the second portion in the steel material.

A constant velocity universal joint is provided which includes an inner ring and an outer ring. A cage is disposed between an outer spherical surface of the inner ring and an inner spherical surface of the outer ring, and has windows in which respective balls are received. The cage has ball contact surface areas with which the balls come into contact, and includes soft portions that are lower in hardness than the ball contact surface areas. The soft portions are formed by local heat treatment at portions of the windows that are kept out of contact with the balls or surface portions around the windows.

A bearing component including a first metallic material and a second metallic material. The first metallic material provides a first carbon content and the second metallic material presents a second carbon content. The first metallic material and the second metallic material have been joined by a diffusion welding process. The diffusion welding process results in a transition zone with a varying carbon content between the first metallic material and the second metallic material. Varying carbon content in the transition zone is within an interval and the interval end points are defined by the carbon contents of the first metallic material and the second metallic material.

A carburized shaft part having a predetermined composition, a C content at a surface layer part of a mass % of 0.60 to 1.00%, at least one hole at an outer circumferential surface, a total volume ratio of martensite and retained austenite of 97% or more at a structure at a position of a 1 mm depth from the outer circumferential surface in an axial direction of the hole and a position of a 20 m depth from the surface of the hole, a maximum retained austenite volume ratio (R1) of 10.0 to 30.0% at a position of a 1 mm depth from the outer circumferential surface in the axial direction of the hole and a range up to a 200 m depth from the surface of the hole, and a retained austenite reduction ratio of 20% or more found from R1 and the retained austenite volume ratio (R2) at a position of a 1 mm depth from the outer circumferential surface in the axial direction of the hole and a position of a 20 m depth from the surface of the hole by the formula (A): =(R1R)/R1100.

A bearing component such as a bearing ring includes a metallic base body and at least one alloy steel coating on the base body, the coating being applied to the base body by deposition welding. The base body is preferably non-alloy steel or cast iron, and the alloy includes at least one carbide-forming transition metal such as niobium, tantalum, zirconium, titanium, hafnium, tungsten, molybdenum, vanadium, or manganese. The coating can form a raceway of the bearing component or a structural element such as a flange. Also a method of forming such a bearing component is provided.

A method of manufacturing a slide of a variable oil pump for a vehicle includes preparing a molded body for a slide of a variable oil pump using prealloy powder including, in percent (%) by weight of the entire composition, 0.45 to 0.55% of carbon (C), 2.8 to 3.2% of chromium (Cr), 0.45 to 0.55% of molybdenum (Mo), 0.35 to 0.5% of manganese (Mn), 0.1 to 0.25% of sulfur (S), and the remainder of iron (Fe) and inevitable impurities. A sintered body is prepared by sintering the molded body. The sintered body is slowly cooled such that a temperature of the sintered body reaches a first temperature range and rapidly cooled when the first temperature range is reached.

A near-eutectoid bearing steel having from 0.7 to 0.9 wt. % carbon, from 0.1 to 0.35 wt. % silicon, from 0.7 to 1.2 wt. % manganese, from 1.0 to 2.0 wt. % chromium, from 0.1 to 0.35 wt. % molybdenum, from 0.2 to 0.6 wt. % nickel, from 0.4 to 1.2 wt. % copper, from 0 to 0.15 wt. % vanadium, from 0 to 0.15 wt. % niobium, from 0 to 0.15 wt. % tantalum, from 0 to 0.2 wt. % cobalt, from 0 to 0.1 wt. % aluminum, from 0 to 0.05 wt. % phosphorous, from 0 to 0.03 wt. % sulphur, from 0 to 0.075 wt. % tin, from 0 to 0.075 wt. % antimony, from 0 to 0.04 wt. % arsenic, from 0 to 0.01 wt. % lead, up to 350 ppm nitrogen, up to 100 ppm oxygen, up to 50 ppm calcium, up to 50 ppm boron, up to 50 ppm titanium, the balance iron, together with any other unavoidable impurities.

A rolling-sliding member that is high in hardness and continues to have a passivation film reliably even after being subjected to a process that does not require any processing for removal of scale, etc., as well as a rolling bearing using the same and a method for manufacturing the rolling-sliding member.

A method for manufacturing a crankshaft for an internal combustion engine with a plurality of journals having a hardened case with a first microstructure. The crankshaft is comprised of a steel comprising between about 0.3 wt % and 0.77 wt % Carbon. The first microstructure of the hardened case of the journals comprises between about 15% and 30% ferrite and a balance of martensite and the resultant subsurface residual stress between 310 MPa and 620 MPa.

A method for manufacturing a crankshaft for an internal combustion engine with a plurality of journals having a hardened case with a first microstructure. The crankshaft is comprised of a steel comprising between about 0.3 wt % and 0.77 wt % Carbon. The first microstructure of the hardened case of the journals comprises between about 15% and 30% ferrite and a balance of martensite and the resultant subsurface residual stress between 310 MPa and 620 MPa.