Patent · US Expired

Method for producing cold-rolled steel sheet

US5078809A · kind A · utility

8Cited by
13References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 17, 1988
Grant dateJan 7, 1992
Priority date
Expiry dateOct 17, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC21D8/0473
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A method for producing cold-rolled steel sheets which comprises the steps of: producing slabs containing 0.001-0.003 wt. % C, 0.004 wt. % or less N and 0.03-0.20 wt. % P, providing that P(wt. %).times.N(wt. %).ltoreq.3.times.10.sup.-4 wt. % is satisfied; hot-rolling the slabs into hot-rolled steel strips; cold-rolling the hot-rolled steel strips at 60-95% reduction ratio into cold-rolled steel strips; and annealing continuously the cold-rolled strips at temperature of recrystallization temperature to Ac.sub.3 transformation point temperature. The slabs further include 0.0005-0.0030 wt. % B. The hot-rolling is performed at finishing temperature ranging Ar.sub.3 transfromation point to Ar.sub.3 transformation +100.degree. C., at cooling temperature of 750.degree. C. and less.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.