Federal-mogul Burscheid Gmbh

Stefan Duerdoth

Peter-Klaus Esser

Rudolf Linde

Christian Herbst-Dederichs

Peter Schmidt

Waldemar Urbatzka

Martin Wenzelburger

A coated piston ring having a base body of chromium steel with more than 10 wt.-% chromium and having an inner circumferential surface, a first flank surface, a second flank surface and an outer circumferential surface. The first flank surface comprises a nitride diffusion layer with a layer thickness of from 5-300 &#x3bc;m, a nitride connecting layer with a layer thickness of from 0.5-15 &#x3bc;m on the nitride diffusion layer, and an oxide layer with a layer thickness of from 0.05-3 &#x3bc;m on the nitride connecting layer. The second flank surface comprises the nitride diffusion layer, and the outer circumferential surface comprises the nitride diffusion layer and a chromium solid particle layer with 0.1-30 vol.-% solid particles, relative to the total volume of the chromium solid particle layer on the nitride diffusion layer.

Piston ring with chromium solid particle wear-prevention layer and corrosion-resistant flank surface

A structured chromium solids particles layer with a network of cracks in which solids particles are embedded, wherein the crack density is 10-250 per mm, the particle size of the solids particles lies in the range of from 0.01-10 &#x3bc;m, the proportion of solids particles in the overall layer is 1-30 vol.-% and the chromium solids particles layer has a microstructure with depressions in the surface of the layer, wherein the proportion of the surface area accounted for by the depressions is 5-80%. A method for producing the structured chromium solids particles layer on a workpiece includes introducing the workpiece into an electrolyte containing a Cr(VI) compound and electrolytically depositing a chromium layer at a current density of 20-100 A/dmand a current yield of 12% or less and then reversing the current direction wherein the solid particles are embedded within the network of cracks.

Structured chrome solid particle layer and method for the production thereof

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Burscheid, Germany

Stefan Duerdoth