Heat-treating method for improving wear-resistance and corrosion-resistance of chromium-plated steel substrate
US6846367B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 2003 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Feb 11, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D5/50
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Disclosed is a method for improving the wear- and corrosion-resistance of a chromium-plated steel substrate by heat-treating the chromium-plated steel substrate under optimum conditions to inhibit a drop in corrosion-resistance of a steel substrate due to fine cracks formed at a chromium layer, and to improve a hardness of the chromium layer. The heat-treating method comprises the steps of: plating the chromium layer onto the steel substrate; and heating the chromium-plated steel substrate in an oxidizing gas environment at above atmospheric pressure to form oxidized layers containing magnetite (Fe3O4) on the surface of the steel substrate, the surface of the steel substrate being partly exposed to the air through penetrating cracks formed in the chromium layer.In accordance with the heat-treating method, the chromium-plated steel substrate having excellent corrosion- and wear-resistance can be easily obtained by plating chromium onto the steel substrate, followed by oxidizing the chromium-plated steel substrate. In addition, the heat-treating method contributes to fewer defects, low manufacturing costs and long life span of chromium plating-related products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.