Non-aging at room temperature ferritic single-phase cold-rolled steel sheet and hot-dip galvanized steel sheet for deep drawing having excellent fabrication embrittlement resistance and paint-bake hardenability and process for producing the same
US5486241A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1994 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | Jun 29, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/005
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a non-aging at room temperature ferritic single-phase cold-rolled steel sheet or hot-dip galvanized steel sheet for deep drawing and having excellent fabrication embrittlement resistance and paint-bake hardenability, by heating a slab comprising, in terms of % by weight, 0.0001 to 0.0015% of C, not more than 1.2% of Si, 0.03 to 3.0% of Mn, 0.01 to 0.15% of P, 0.0010 to 0.020% of S, 0.005 to 0.1% of Al, 0.0001 to 0.0080% of N and 0.0001 to 0.0030% of B and optionally 0.1 to 3% of Cr with the balance consisting of Fe and unavoidable impurities, hot-rolling the heated slab at a finishing temperature of not lower than (Ar.sub.3 --100).degree. C., cooling the hot-rolled coil within 1 sec after the hot rolling at a rate of not less than 50.degree. C./sec from the finishing temperature to a temperature in the range of from 600.degree. to 750.degree. C. and coiling the cooled strip in said temperature range, cold-rolling the coil with a reduction ratio of not lower than 60% and conducting continuous annealing or continuous hot-dip galvanizing in the temperature range of from 600.degree. to 900.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.