Method for manufacturing high-Si cold rolled steel sheet having excellent chemical conversion properties
US8911574B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2011 |
| Grant date | Dec 16, 2014 |
| Priority date | — |
| Expiry date | Dec 8, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23G1/081
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for manufacturing high-Si cold rolled steel sheets includes heating a cold rolled steel sheet with a direct flame burner (A) having an air ratio of not more than 0.89 when the temperature of the cold rolled steel sheet that is being increased is in the temperature range of not less than 300° C. and less than Ta° C., subsequently heating the cold rolled steel sheet with a direct flame burner (B) having an air ratio of not less than 0.95 when the temperature of the cold rolled steel sheet is in the temperature range of not less than Ta° C. and less than Tb° C., and subsequently soak-annealing the cold rolled steel sheet in a furnace having an atmospheric gas composition which has a dew point of not more than −25° C. and contains 1 to 10 volume % of H2 and the balance of N2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.