Title:
A shot peening method for forming a gear excellent in abrasion resistance and pitching intensity
Document Type and Number:
Japanese Patent JP6191906
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a shot-peening method by which tooth surface fatigue strength of a gear can be excellently improved.SOLUTION: In the shot-peening method of the present invention, two-stage shot-peening is performed for projecting on the gear after being subjected to carburization treatment by using a grit having a hardness of 700HV or more under a condition of shot air pressure of 0.2-0.6 MPa. In the first stage, the grit having a particle size φ within the range of 0.3-1.0 mm is used and in the second stage, the grit having a particle size φ within the range of 0.05-0.2 mm is used. As a result, maximum compressive residual stress up to a depth position of 30 μm from a surface layer of a tooth surface of the gear is set to 1,500 MPa or more, compressive residual stress up to a depth position of 75 μm from the surface layer of the tooth surface is set to 600 MPa or more, and surface roughness Ra of the tooth surface is also set to 0.8 μm or less.
Inventors:
Naoki Umemori
Ryohei Ishikura
Ryohei Ishikura
Application Number:
JP2013086314A
Publication Date:
September 06, 2017
Filing Date:
April 17, 2013
Export Citation:
Assignee:
Daido Steel Co., Ltd.
International Classes:
B24C1/10; B23F19/00; B24C11/00; C21D7/06; C23C8/22; C23C10/60
Domestic Patent References:
| JP2007307678A | ||||
| JP2008057017A | ||||
| JP2007291486A | ||||
| JP2002030344A |
Foreign References:
| US6038900 | ||||
| US20110135414 |
Attorney, Agent or Firm:
Ryuji Harikawa
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