Method for manufacturing high-strength cold-rolled steel strip excellent in press-formability
US4336080A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1980 |
| Grant date | Jun 22, 1982 |
| Priority date | — |
| Expiry date | Nov 20, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for manufacturing a high-strength cold-rolled steel strip excellent in press-formability, which comprises the steps of: preparing a slab of an aluminum-killed steel consisting essentially of, in weight percentage: ______________________________________ Carbon from 0.02 to 0.06%, Manganese from 0.06 to 0.25%, Phosphorus from 0.01 to 0.06%, Soluble aluminum from 0.020 to 0.060%, Nitrogen up to 0.005%, and ______________________________________ PA1 the balance iron and incidental impurities; hot-rolling said slab to prepare a hot-rolled steel strip; coiling said steel strip at a temperature within the range of from 650.degree. to 770.degree. C.; cold-rolling said hot-rolled steel strip thus coiled to prepare a cold-rolled steel strip; subjecting said cold-rolled steel strip to a continuous annealing treatment for a prescribed period of time at a temperature within the range of from 750.degree. to 880.degree. C.; cooling said cold-rolled steel strip continuously annealed at a cooling rate of at least: exp {-5.6 (Cwt. %.gamma.+Mn wt. %/6+Si wt. %/24)+7.8} .degree.C./sec from a temperature region of from Ar.sub.1 to Ar.sub.1 +60.degree. C. to convert the structure thereof into a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.