Title:
CASE HARDENED STEEL FOR BEARING EXCELLENT IN ROLLING FATIGUE CHARACTERISTIC
Document Type and Number:
Japanese Patent JP2014189895
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a case hardened steel excellent in rolling fatigue characteristic.SOLUTION: The case hardened steel of the present invention has an estimated value of square root of a projected area of the maximum oxide-based inclusion (√area max) controlled to 40 μm or less and contains C:0.32 to 0.48%, Si:0.5% or less (excluding 0%), Mn:1.5% or less (excluding 0%), P:0.03% or less (excluding 0%), S:0.01% or less (excluding 0%), Cr:0.85 to 1.50%, Al:0.005 to 0.06%, Nb:0.01 to 0.09%, N:0.005 to 0.020% and the balance iron with inevitable impurities. In the case hardened steel, a density of Nb carbonitride having an average particle diameter of 2 μm or more is 10 pieces /cmor less and a density of Nb carbonitride having an average particle diameter of 0.01 to 0.1 μm is 1 piece /μmor more.
Inventors:
SHINTO YOSUKE
OWAKI AKIHIRO
OWAKI AKIHIRO
Application Number:
JP2013069566A
Publication Date:
October 06, 2014
Filing Date:
March 28, 2013
Export Citation:
Assignee:
KOBE STEEL LTD
International Classes:
C22C38/00; C22C38/26; C22C38/50; C21D6/00; C21D8/06
Domestic Patent References:
| JP2012224928A | 2012-11-15 | |||
| JP2006063402A | 2006-03-09 | |||
| JP2000054069A | 2000-02-22 | |||
| JP2007284739A | 2007-11-01 | |||
| JP2005054937A | 2005-03-03 | |||
| JP2010248630A | 2010-11-04 |
Foreign References:
| WO1999005333A1 | 1999-02-04 |
Attorney, Agent or Firm:
Hisakazu Ueki
Hisahiko Ueki
Tadashi Sugawa
Hiroaki Ito
Akemi Takeoka
Hisahiko Ueki
Tadashi Sugawa
Hiroaki Ito
Akemi Takeoka