Method of manufacturing high carbon cold-rolled steel sheet
US8052812B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2006 |
| Grant date | Nov 8, 2011 |
| Priority date | — |
| Expiry date | Aug 24, 2026 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high carbon cold-rolled steel sheet having both excellent stretch-flange formability and excellent homogeneity of hardness in the sheet thickness direction is provided by a manufacturing method having the steps of: hot-rolling a steel containing 0.2 to 0.7% C by mass at finishing temperatures of (Ar3 transformation point −20° C.) or above to prepare a hot-rolled sheet; cooling the hot-rolled sheet to temperatures of 650° C. or below at cooling rates from 60° C./s or larger to smaller than 120° C./s; coiling the hot-rolled sheet after cooling at coiling temperatures of 600° C. or below; cold-rolling the coiled hot-rolled sheet at rolling reductions of 30% or more to prepare a cold-rolled sheet; and annealing the cold-rolled sheet at annealing temperatures from 600° C. or larger to Ac1 transformation point or lower.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.