High tensile strength hot-dip galvannealed steel sheet having excellent coated-layer adhesiveness and method for producing same
US9181613B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2011 |
| Grant date | Nov 10, 2015 |
| Priority date | — |
| Expiry date | Apr 20, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A high tensile strength hot-dip galvannealed steel sheet having excellent coated-layer adhesiveness in which the hot-dip galvannealed layer does not peel off from a base steel sheet even in being subjected to working accompanied by sliding and a method for producing the same are provided. In the high tensile strength hot-dip galvannealed steel sheet, a hot-dip galvannealed layer is formed on the surface of the base steel sheet, the base steel sheet contains Si by 0.04-2.5%, and, when the surface roughness of the base steel sheet after the hot-dip galvannealed layer is removed by dissolution with an acid is measured for a plurality of locations by a laser microscope, the arithmetic mean inclination angle (RΔa) is 23.0° or more and the root mean square inclination angle (RΔq) is 29.0° or more in 60% or more of all of the locations measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.