Patent ID: 8747573

Claim:
A method for producing corrosion-resistant surfaces of nitrated or nitrocarburated steel components, wherein the surfaces have roughness profile heights Rz of Rz≦1.5 μm, said method comprising the following method steps: oxidizing the surfaces of the nitrated or nitrocarburated components in a first oxidation step; further oxidizing the component surfaces during at least one immediately following oxidation step, wherein the first and the at least one immediately following oxidation steps use respective first and second molten salt baths that have different compositions from one another and the oxidation steps have identical or different processing conditions: wherein the first molten salt bath comprises: 20-50% by weight of NaNO 3 0-40% by weight of KNO 3 0-5% by weight of NaNO 2 20-60% by weight of NaOH 0-20% by weight of KOH 3-25% by weight of Na 2 CO 3 3-15% by weight of K 2 CO 3 1-30% by weight of Li 2 CO 3 1-10% by weight of Li 2 NO 3 ; and 1-10% by weight of LiCl and wherein the second molten salt bath comprises: 10-50% by weight of NaNO 3 0-40% by weight of KNO 3 0-20% by weight of NaNO 2 20-70% by weight of NaOH 0-60% by weight of KOH 3-30% by weight of Na 2 CO 3 3-30% by weight of K 2 CO 3 ; and 0-10% by weight of Li 2 CO 3 ; and polishing the surfaces in a final processing step that immediately follows a last oxidation.