Title:
HARD CHROMIUM-PLATED SLIDING MEMBER, PISTON RING AND PROCESS FOR MANUFACTURING THEM
Document Type and Number:
Japanese Patent JP3857590
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a hard chromium-plated sliding member having high wear resistance, baking resistance and peeling resistance, even at elevated temperature and under a high pressure, a piston ring and a process for manufacturing them.
SOLUTION: The piston ring 1 has a hard chromium-plating film 20 made of at least 4 layers comprising an innermost layer 21, middle layers 22, 23 and an outermost layer 24, each comprising a hard chromium-plating layer. The hard chromium-plating film contains 0.1-0.15 mass% (1,000-1,500 ppm) hydrogen and therefore has a distorted crystal lattice. Within each layer, multiple- layer fine cracks 20a, each of which is continuously formed across multiple neighboring hard chromium-plating films, and single-layer fine cracks 20b, each of which is formed within a single layer without extending into other neighboring layers, are formed.
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Inventors:
Etsuo Tamegai
Application Number:
JP2002018704A
Publication Date:
December 13, 2006
Filing Date:
January 28, 2002
Export Citation:
Assignee:
Nippon Piston Ring Co., Ltd.
International Classes:
C25D7/00; F02F5/00; C25D5/14; C25D5/18; F16J9/26; (IPC1-7): C25D7/00; C25D5/14; C25D5/18; F02F5/00; F16J9/26
Domestic Patent References:
| JP2304266A | ||||
| JP10018052A | ||||
| JP2001089873A |
Foreign References:
| WO2001048267A1 |
Attorney, Agent or Firm:
Kazuhiro Kitazawa
Shin Koizumi
Akiko Ichikawa
Shin Koizumi
Akiko Ichikawa
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