Hydraulic piston and process for its surface treatment

摘要

Hydraulic piston has a layer sequence arranged on the piston surface. The sequence consists of an oxide layer having a thickness of at least 1 microns arranged directly on the piston surface, a connecting layer made mainly of nitrides arranged below the oxide layer, and a diffusion layer made from nitrogen in dissolved form and/or deposited nitrides arranged below the connecting layer. The connecting layer is at least 8 microns thick. An Independent claim is also included for a process for surface treating a hydraulic piston comprising nitro-carburizing the piston in a gas medium, oxidizing the piston in a medium which releases oxygen, and mechanically processing the oxidized surface.