Thin steel sheet having excellent rectangular drawability and production method thereof
US6103394A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 1998 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Mar 3, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12229
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A thin steel sheet having excellent rectangular drawability is produced by completing roughing rolling of steel containing C: 0.02 wt % or less, Si: 0.5 wt % or less, Mn: 1.0 wt % or less, P: 0.15 wt % or less, S: 0.02 wt % or less, Al: 0.01 to 0.10 wt %, N: 0.008 wt % or less, at least one of Ti: 0.001 to 0.20 wt % and Nb: 0.001 to 0.15 wt %, the balance comprising Fe, and inevitable impurities, in the temperature region of 950.degree. C. to the Ar.sub.3 transformation temperature: performing finish rolling at a reduction of over 70% under lubrication in the temperature region of the Ar.sub.3 transformation temperature to 500.degree. C.; pickling the sheet; annealing the resultant hot rolled sheet under conditions which satisfy the equations (1) and (2) below: EQU (T+273) (20+log t).gtoreq.2.50.times.10.sup.4 (1) EQU 745.ltoreq.T.ltoreq.920 (2) wherein T: hot rolled sheet annealing temperature (.degree. C.) PA1 t: hot rolled sheet annealing time (sec); cold rolling at a reduction of 50 to 95%; and then recrystallization annealing; to satisfy the following relations: EQU (r.sub.L +r.sub.C)/2-r.sub.D .gtoreq.0.67, and EQU (r.sub.L +2r.sub.D +r.sub.C)/4.gtoreq.2.7, wherein r.sub.L : …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.