Piston ring
A piston ring comprises a martensitic stainless steel ring having a nitrided layer formed in the surface portion thereof, and a titanium nitride film coated on the outer sliding surface of the ring by an ion-plating process. According to a first embodiment of the present invention, the titanium nitr...
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Main Author | |
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Format | Patent |
Language | English |
Published |
13.10.1992
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Subjects | |
Online Access | Get full text |
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Summary: | A piston ring comprises a martensitic stainless steel ring having a nitrided layer formed in the surface portion thereof, and a titanium nitride film coated on the outer sliding surface of the ring by an ion-plating process. According to a first embodiment of the present invention, the titanium nitride film has a nitrogen concentration which is gradually increased toward the top surface thereof to gradually lower a toughness of the film toward the top surface and to make a surface portion of the film more brittle than the other portion of the film. On the other hand, according to a second embodiment of the present invention, the titanium nitride film has a nitrogen concentration which is gradually decreased toward the top surface and to make a surface hardness of the film HV 1800 or less. |
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Bibliography: | Application Number: US19910715541 |