Title:
BEARING PART, BEARING AND BEARING PART INSPECTION METHOD
Document Type and Number:
WIPO Patent Application WO/2011/122632
Kind Code:
A1
Abstract:
Disclosed are an inspection method for quantitatively and simply assuring nitrogen concentration in a bearing part which has undergone a carbonitriding treatment, as well as bearing parts and a bearing in which the nitrogen concentration is quantitatively assured. An inner ring (1), outer ring (2) and ball (3), which are the bearing parts, are formed from JIS standard SUJ2 and have a carbonitrided layer formed on the surface. After heat treatment at a heating temperature of 500°C and a retention time of 1 hour, the Vickers hardness of a position at a depth of 30 µm from the surface is at least 130 HV higher than the Vickers hardness of the core, which is a region where the carbonitrided layer has not been formed in the thickness direction of the bearing part.
Inventors:
OHKI CHIKARA (JP)
Application Number:
PCT/JP2011/057849
Publication Date:
October 06, 2011
Filing Date:
March 29, 2011
Export Citation:
Assignee:
NTN TOYO BEARING CO LTD (JP)
OHKI CHIKARA (JP)
OHKI CHIKARA (JP)
International Classes:
C23C8/32; C21D1/06; C21D9/40; F16C19/02; F16C33/62; F16C33/64
Foreign References:
| JPH05240253A | 1993-09-17 | |||
| JPH11304795A | 1999-11-05 | |||
| JP2962817B2 | 1999-10-12 | |||
| JP2009229288A | 2009-10-08 |
Other References:
See also references of EP 2554709A4
HYOJIRO KURABE ET AL.: "Rolling Fatigue Characteristics of Carburized or Carbonitrided 1% Cr Steel at Elevated Temperatures", IRON AND STEEL, vol. 11, 1967, pages 1305
YOUICHI WATANABE ET AL.: "Effects of Nitrogen Content on Microstructure and Resistance to Softening during Tempering of Carbo-Nitrided Chromium Alloy Steels", HEAT TREATMENT, vol. 40, 2000, pages 18
CHIKARA OHKI: "Nitrogen Concentration Distribution Prediction in SUJ2 Subjected to Carbonitriding Treatment", IRON AND STEEL, vol. 93, 2007, pages 220
HYOJIRO KURABE ET AL.: "Rolling Fatigue Characteristics of Carburized or Carbonitrided 1% Cr Steel at Elevated Temperatures", IRON AND STEEL, vol. 11, 1967, pages 1305
YOUICHI WATANABE ET AL.: "Effects of Nitrogen Content on Microstructure and Resistance to Softening during Tempering of Carbo-Nitrided Chromium Alloy Steels", HEAT TREATMENT, vol. 40, 2000, pages 18
CHIKARA OHKI: "Nitrogen Concentration Distribution Prediction in SUJ2 Subjected to Carbonitriding Treatment", IRON AND STEEL, vol. 93, 2007, pages 220
Attorney, Agent or Firm:
Fukami Patent Office, p. c. (JP)
Patent business corporation Fukami patent firm (JP)
Patent business corporation Fukami patent firm (JP)
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Claims: