Method for producing cold rolled steel sheets having a noticeably excellent formability
US4368084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1981 |
| Grant date | Jan 11, 1983 |
| Priority date | — |
| Expiry date | May 28, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0473
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Non-ageing cold rolled steel sheets having a very excellent formability are produced by hot rolling a steel consisting of not more than 0.008% of C, not more than 0.20% of Si, 0.04-0.30% of Mn, not more than 0.03% of P, 0.01-0.10% of Al, a content of Al being more than N%.times.4, not more than 0.02% of S, not more than 0.01% of N, 0.01-0.07% of Nb, a content of Nb being C%.times.3-{C%.times.8+0.02}%, and the remainder being substantially Fe, at a total reduction of not less than 90%, a rolling speed of not less than 40 m/min in the finishing rolling and a finishing temperature of not lower than 830.degree. C., coiling the hot rolled strip at a temperature of 600.degree.-800.degree. C., cold rolling the coiled strip following a conventional manner to obtain a cold rolled strip having final gauge and then continuous annealing or hot-dip galvanizing the cold rolled strip within a temperature range of 700.degree.-900.degree. C. for 10 seconds-5 minutes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.