Method and apparatus for manufacturing Si-containing cold rolled steel sheets
US9243334B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2012 |
| Grant date | Jan 26, 2016 |
| Priority date | — |
| Expiry date | Jan 21, 2033 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0478
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
This invention provides methods and apparatuses which can manufacture Si-containing cold rolled steel sheets exhibiting excellent chemical conversion properties even if a chemical conversion treatment solution is used at a lower temperature while minimally suppressing the generation of sludge as well as reducing running costs. The method includes steps of cold rolling a steel containing 0.5 to 3.0 mass % Si, continuously annealing the cold rolled steel sheet, pickling the surface of the continuously annealed cold rolled steel sheet, and repickling the surface of the pickled steel sheet with a non-oxidative acid. The repickling is performed such that a repickling solution is sampled continuously or periodically, an acid concentration in the sampled solution is measured, and the acid concentration in the repickling solution is regularly controlled within a prescribed concentration range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.