Title:
SURFACE TREATMENT METHOD FOR METAL PRODUCT AND METAL PRODUCT
Document Type and Number:
WIPO Patent Application WO/2017/199918
Kind Code:
A1
Abstract:
Provided is a surface treatment method capable of continuously forming a uniform nanocrystalline structure along the surface of a metal product regardless of whether the metal product is hard or soft. In the present invention, a substantially spherical spray powder having a median diameter of 1-20 µm and a fall velocity in the air of 10 sec/m or more is sprayed onto a metal product at a spray pressure of 0.05-0.5 MPa. Thus even when the metal product is made of a soft material in a range from the surface of the metal product to a predetermined depth along the surface, it is possible to form a uniform continuous nanocrystalline structure layer in which nanocrystals are micronized to an average crystal grain size of not more than 300 nm, preferably not more than 100 nm, without forming a laminar worked structure, impart a high compression residual stress of from about -180 MPa up to the order of -1200 MPa, and strengthen the surface of the metal product.
Inventors:
MASE KEIJI (JP)
ISHIBASHI SHOZO (JP)
KONDO YUSUKE (JP)
ISHIBASHI SHOZO (JP)
KONDO YUSUKE (JP)
Application Number:
PCT/JP2017/018229
Publication Date:
November 23, 2017
Filing Date:
May 15, 2017
Export Citation:
Assignee:
FUJI MFG CO LTD (JP)
International Classes:
C22F1/04; B24C1/10; C21D7/06; C22F1/00
Foreign References:
| JP3879059B2 | 2007-02-07 | |||
| JP5341971B2 | 2013-11-13 | |||
| JP2009091606A | 2009-04-30 | |||
| JP3150048U | 2009-04-30 |
Other References:
See also references of EP 3460090A4
Attorney, Agent or Firm:
OGURA & CO. (JP)
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