Title:
SURFACE TREATED STEEL PRODUCT, METHOD FOR PRODUCTION THEREOF AND CHEMICAL CONVERSION TREATMENT SOLUTION
Document Type and Number:
WIPO Patent Application WO/2002/068715
Kind Code:
A1
Abstract:
A chemical conversion film having a specified thickness and containing a potassium compound in a specified amount is formed on the surface of a screw of a joint portion of an oil well steel pipe by using a chemical conversion treatment solution added with a potassium ion in a specified amount. The chemical conversion treatment solution allows the stable formation of a phosphate chemical conversion film on a joint portion of an oil well pipe steel product which contains 0.5 to 13 % of Cr.
Inventors:
IZAWA MASARU (JP)
GOTO KUNIO (JP)
GOTO KUNIO (JP)
Application Number:
PCT/JP2002/001521
Publication Date:
September 06, 2002
Filing Date:
February 21, 2002
Export Citation:
Assignee:
SUMITOMO METAL IND (JP)
IZAWA MASARU (JP)
GOTO KUNIO (JP)
IZAWA MASARU (JP)
GOTO KUNIO (JP)
International Classes:
C23C22/07; C23C22/00; C23C22/08; C23C22/12; C23C22/18; C23C22/50; C23C22/62; (IPC1-7): C23C22/07; B05D7/14; C23C22/12; C23C22/18; C23C22/50; C23C22/62
Foreign References:
| JPH09263958A | 1997-10-07 | |||
| JPS63134672A | 1988-06-07 | |||
| US3798074A | 1974-03-19 | |||
| JPS5782478A | 1982-05-22 | |||
| JPH0540034A | 1993-02-19 | |||
| US5238506A | 1993-08-24 | |||
| EP0786616A1 | 1997-07-30 |
Other References:
See also references of EP 1382718A4
Attorney, Agent or Firm:
Hirose, Shoichi (4-2 Nihonbashi Honcho 4-chome Chuo-ku, Tokyo, JP)
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