The non-porous and ductile matt nickel layer has the benefit of excellent corrosion resistence, also when exposed to chlorides and even hydrochloric acid, but not nitric acid. It also has a leveling effect, ductile properties under load exposure, a nearly unlimited maximum layer thickness, good mechanical processing properties as well as good temperature resistence of up to 550°C. Furthermore, nickel plating is eminently suitable for partial coating and as a "repair layer". Compact and crack-free layers can be achieved with comparatively little effort. The Vickers hardness of the matt nickel layer is 200 - 250 HV 0.1.