Method of manufacturing a cold-rolled steel sheet having a good deep drawability
US4857117A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1988 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Feb 25, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0473
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of manufacturing a cold-rolled steel sheet having a good deep drawability is disclosed, wherein a hot rolled steel sheet having a composition of C.ltoreq.0.0035%, Si.ltoreq.1.0%, Mn.ltoreq.1.0%, Al:0.005-0.10%, P.ltoreq.0.15%, N.ltoreq.0.0035%, S.ltoreq.0.015%, Ti: (48/14N(%)+48/32S(%)) or {4.times.(C(%)+N(%))}.about.(3.48/12C(%)+48/14N(%)+48/32S(%)) and Nb: (0.2.93/12C(%)).about.(93/12C(%))% is cooled within 2 seconds after the completion of finisher rolling and then at an average cooling rate of not less than 10.degree. C./sec until it arrives at a coiling step, and then the cooled steel sheet is coiled at a temperature of not more than 710.degree. C., subjected to a cold rolling at a reduction of not less than 50%, which was subjected to a continuous annealing in a heatcycle inclusive of heating from 400.degree. C. to 600.degree. C. at a heating rate of not less than 5.degree. C./sec and soaking at a temperature range of 700.degree. C.-Ac.sub.3 point for 1 second or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.