Method for producing a piston ring

Patent metadata

Field	Value
Publication number	US-11060609-B2
Application number	US-201816610747-A
Country	US
Kind code	B2
Filing date	Jul 13, 2018
Priority date	Jul 26, 2017
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A piston ring is produced from a main body made of steel or cast steel and comprising a running face, an inner circumferential surface, upper and lower flank regions, and transition regions from the running face to the respective flank region, by coating the running face and the transition regions with a first chromium layer, removing this first chromium layer at the running face down to the base material of the main body, providing at least the running face of the layer-free main body with a nitride layer, and, finally, coating the running face and the transition regions with at least one further chromium layer.

First claim

The invention claimed is:

1. A method for producing a piston ring, comprising providing a main body made of steel or cast steel, the main body comprising a running face, an inner circumferential surface, upper and lower flank regions, and transition regions from the running face to the respective flank region, then coating the running face and the transition with a first chromium layer, removing this first chromium layer at the running face down to the steel or cast steel of the main body, then providing at least the running face with a nitride layer, and, finally, coating the running face and the transition regions with at least one further chromium layer.

2. The method according to claim 1 , wherein the first chromium layer of a thickness no greater then 15 μm.

3. The method according to claim 1 , wherein the providing at least the running face with the nitride layer comprises providing also at least one of the upper and lower flank regions with the nitride layer.

4. The method according to claim 1 , wherein the nitride layer is of a thickness of >0 to 30 μm.

5. The method according to claim 1 , wherein the further chromium layer of a thickness between 5 and 20 μm.

6. A piston ring, produced according to the method of claim 1 .

7. A piston ring, comprising a main body made of steel or cast steel, the main body comprising a running face, an inner circumferential surface, upper and lower flank regions, and transition regions from the running face to the respective flank regions, on at least the running face a nitride layer overlaid with a chromium layer, and a chromium layer, but no nitride layer, on the transition regions.

8. The method according to claim 1 , wherein the providing at least the running face with the nitride layer comprises providing also both the flank regions with the nitride layer.

Assignees

• Fed Mogul Burscheid Gmbh

Inventors

• Esser Peter
• Hoppe Steffen
• Meyer Klaus

Classifications

• F16J9/26 Primary

  characterised by the use of particular materials · CPC title

• C23C8/02 Primary

  Pretreatment of the material to be coated (C23C8/04 takes precedence) · CPC title

• C25D5/14

  two or more layers being of nickel or chromium, e.g. duplex or triplex layers · CPC title

• C23C28/00

  Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D · CPC title

• C23C28/32

  including at least one pure metallic layer · CPC title