Continously annealed cold-rolled steel sheet excellent in balance between deep drawability and resistance to secondary-work embrittlement and method for manufacturing same
US5531839A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1995 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 28, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0473
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A continuously annealed cold-rolled steel sheet excellent in balance between deep drawability and resistance to secondary-work embrittlement, which consists essentially of: under 0.0030 wt. % carbon, up to 0.05 wt. % silicon, from 0.05 to 0.20 wt. % manganese, up to 0.02 wt. % phosphorus, up to 0.15 wt. % sulfur, from 0.025 to 0.06 wt. % soluble aluminum, up to 0.0030 wt. % nitrogen, from 0.02 to 0.10 wt. % titanium, from 0.0003 to 0.0010 wt. % boron, and the balance being iron and incidental impurities, where a value of an index (X) representing a content rate of titanium to boron, as calculated by specific formulae, is of from 9.2 to 11.2. The above-mentioned continuously annealed cold-rolled steel sheet is manufactured by: carrying out a finishing-rolling in a hot-rolling of a steel slab having the above-mentioned chemical composition so that a reduction rate distribution function (Y) as expressed by another specific formula is satisfied; completing the finishing-rolling at a temperature of from 880.degree. to 920.degree. C.; then coiling the resultant hot-rolled steel strip; then cold-rolling the hot-rolled steel strip at an accumulative reduction rate of at least 70%; and then…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.