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.

Provided is a steel for carbonitrided bearing which excels in hardenability and also excels in toughness, wear resistance, and surface-originated flaking life after quenching and tempering. A steel for carbonitrided bearing of the present embodiment has a chemical composition containing, in mass %, C: 0.22 to 0.45%, Si: not more than 0.50%, Mn: 0.40 to 1.50%, P: not more than 0.015%, S: not more than 0.005%, Cr: 0.30 to 2.0%, Mo: 0.10 to 0.35%, V: 0.20 to 0.40%, Al: 0.005 to 0.10%, N: not more than 0.030%, and O: not more than 0.0015%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2).
1.20<0.4Cr+0.4Mo+4.5V<2.60(1)
2.7C+0.4Si+Mn+0.8Cr+Mo+V>2.20(2)

A steel alloy providing from 0.05 to 0.25 wt. % carbon, from 10 to 14 wt. % chromium, from 1.5 to 4 wt. % molybdenum, from 0.3 to 1.2 wt. % vanadium, from 0.3 to 3 wt. % nickel, from 6 to 11 wt. % cobalt from 0.05 to 0.4 wt. % silicon, from 0.1 to 1 wt. % manganese, from 0.02 to 0.06 wt. % niobium, optionally one or more of the following elements from 0 to 2.5 wt. % copper from 0 to 0.1 wt. % aluminum, from 0 to 250 ppm nitrogen, from 0 to 30 ppm boron, and the balance iron, together with any unavoidable impurities, wherein the alloy has a Ni.sub.eq of greater than 11.5, the Ni.sub.eq being defined by the formula Ni.sub.eq=Ni+Co+(0.5Mn)+(30C), in wt. %.

A bearing part is composed of a chromium molybdenum steel, and includes a raceway surface or a rolling contact surface. A precipitated compound composed of at least one of a carbide, a nitride, and a carbonitride exist in the raceway surface or the rolling contact surface. An area ratio of the precipitated compound in the raceway surface or the rolling contact surface is more than or equal to 3%. An average grain size of the precipitated compound in the raceway surface or the rolling contact surface is less than or equal to 0.3 m.

A rod end includes a shaft and a head extending from the shaft. The head has an opening extending therethrough. The rod end includes a spherical bearing rotatably disposed in the opening. The spherical bearing is manufactured from an austenitic stainless steel alloy that includes 16 to 17 weight percent chromium and 0.1 to 0.18 weight percent nitrogen.

A bearing assembly includes an inner ring with an inner raceway and disposable about a first member and an outer ring with an outer raceway disposed about the inner ring. A middle ring is disposed between the inner and outer rings and has an inner intermediate raceway and an outer intermediate raceway and is configured to connect with a second member so as to be rotatable about a central axis through the first member. A first set of rolling elements is disposed between the inner ring and the middle ring and a second set of rolling elements is disposed between the outer ring and the middle ring. The outer ring is sized such that a ratio of the outside diameter to the axial width is greater than eight to one (8:1) and the middle ring is formed of a material different than the inner and outer rings.

A rolling bearing providing a first ring and a second ring in relative rotation one each other, and at least one row of rolling elements being arranged between the said rings. At least one the rings is made by metal injection molding process including the successive steps of mixing a metal powder with a thermoplastic binder, forming a part by injection of the mixed powder in a closed die, debinding such a formed part in a furnace, sintering to densify the part, and quenching to set a ring hardness, to improve wear resistance and fatigue life.

A martensitic stainless steel containing, by mass %, C: 0.20% to 0.40%, N: 0.1% or less, Mo: 3% or less, and Cr: 12.0% to 16.0%, such that 0.3%C+N0.4% and a PI value (=Cr+3.3Mo+16N) is 18 or more, with the remainder being substantially Fe and unavoidable impurities is quenched from a temperature of 1,030 C. to 1,140 C. and subjected to a subzero treatment and tempering so as to obtain a prior austenite crystal grain size of a surface layer of 30 m to 100 m and a surface hardness of 58 HRc to 62 HRc.

In one aspect of the present invention, a method for manufacturing a bearing component includes: a preparation step of preparing a ring-shaped member of steel having a radially inner surface, a radially outer surface, and a thickness which is a distance between the radially inner surface and the radially outer surface; and a heat treatment step of performing a heat treatment to locally heat one of the radially inner surface and the radially outer surface to a heat treatment temperature and subsequently cool the one of the radially inner surface and the radially outer surface, the method satisfying S930/(0.3477 W.sup.21.594 W0.804), where S represents an average temperature increasing rate (unit: C./sec) applied when the surface is heated and W represents the thickness (unit: mm).

An inner-flanged bushing for a hydraulic breaker is a tubular shape having an inner flange and is made of a steel containing at least 0.55% and less than 0.70% by mass of carbon, at least 0.15% and less than 0.35% by mass of silicon, at least 0.4% and less than 0.9% by mass of manganese, at least 0.4% and less than 1.3% by mass of chromium, and at least 0.10% and less than 0.55% by mass of molybdenum, with the balance being iron and unavoidable impurities. The bushing includes a base region having a hardness of at least 30 HRC and less than 45 HRC, and a quench hardened layer formed on an inner periphery side of the base region to include an inner peripheral surface of a region including the inner flange, the quench hardened layer having a hardness of at least 55 HRC and less than 63 HRC.