摘要:
A structure (1) supporting a differential (10) rotatably includes an inner ring (3a-3d) arranged at the differential (10), an outer ring (2a-2d) arranged at an external peripheral portion (19a,19b) formed to surround the differential (10), and a tapered roller (4a-4b) rolling between the inner ring (3a-3b) and the outer ring (2a-2b). At least any one of the inner ring (3a-3d), the outer ring (2a-2d), the tapered roller(4a-4d), the shaft and gear components are made of steel and are carbonitrided, quenched, cooled and subjected to a secondary quench hardening treatment. The hardened components have a carbo-nitrided layer with an austenite grain number falling within a range exceeding 10, which provides a fracture stress value of at least 2650 MPa and has a hydrogen content of no more than 0.5 ppm. Thus the structure can be provided with increased anti-crack strength and dimensional stability, and increased rolling contact fatigue life.
摘要:
An inner ring and an outer ring are composed as follows. These members are fabricated with a steel for bearing containing carbon 0.6 wt% or higher. A carbonitrided layer is formed in a raceway surface. The amount of residual austenite at a position of 2% Da depth in the raceway surface is determined to be 1.0 vol% or lower. Hardness at the position of 2% Da depth is set to be HRC58 or more. Nitrogen content (Np) at the position of 2% Da depth is 0.05 wt% or more. A multiple Gd of an impression resistance expressed with the following formula (1) is 1.6 or more,Gd = (H0.2/500) + 2·Np wherein in the formula, H 0.2 is meant by Vickers hardness at the position of 2% Da depth.
摘要:
Es werden ein Verfahren und eine Anlage zur Wärmebehandlung von Teilen angegeben, womit vor dem Glühen zum Härten der Teile (11) in einem Homogenisierungsofen (16) unter Schutzgas in einer vorgeschalteten Vorwärmstation (14) zuvor ein Aufheizen der Teile (11) an Luft erfolgt. Auf diese Weise werden die Gesamtkosten der Anlage (10) reduziert, da der Ofen (16) zur Glühbehandlung unter Schutzgas deutlich verkürzt werden kann. Zur Härtung der Teile (11) ist eine Härtungsstation (18) vorgesehen, die vorzugsweise über einen seitlichen Beschickungskanal (44) unmittelbar mit der Auslauföffnung (40) des Glühofens (16) gekoppelt ist. Innerhalb der Härtungsstation (18) können Teile in mehreren Ebenen auf einem Teileträger (48) aufgenommen werden (Fig. 1).
摘要:
A rolling bearing characterized in that at least the fixed side bearing ring thereof has a lower bainite structure formed by isothermal transformation treatment, a hardness of a HRC of 54 to 64, an amount of retained austenite of 5 % or less, and an area percentage of carbide particles having a length of 0.8 mu m or more relative to the total secondary eutectoid carbide area of 20 % or less. The rolling bearing is reduced in the occurrence of white layers.
摘要:
Method for the production of a part of a rolling bearing, such as a ring for a ball bearing. The starting material used is a grade of steel containing .90 1.00 % C; at most 0.15 % Si; 0.25 - 0.45 % Mn; at most 0.0015 % P; at most 0.010 % S; 1.30 - 1.50 % Cr; at most .15 % Ni; 0.20 - 0.23 % Mo; at most 0.20 - 0.23 % Cu; at most 20 ppm Ti; at most 8 ppm O. Before subjecting this grade of steel to a quenching and tempering treatment, the shaped item is subjected to plastic deformation in the hot or cold state. The mechanical properties and in particular the anticipated life under severe stress improve as a result.
摘要:
A method for the manufacture of components made of steel subject to heavy stress, load and/or wear, such as rolling bearing elements,
starting from a steel having an austenite carbon content at hot forming temperature of about 800 - 1100°C of 0.55-0.85 wt%, hot forming of the components above Al of the steel, hardening of the components directly from the hot forming temperature, in air, possibly forced convection aided by addition of water, hard machining of the components to their final dimensions, surface finishing of the components.