Patent · US Expired

Process for producing hot-rolled steel sheet having high r value

US4769088A · kind A · utility

3Cited by
1References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 6, 1987
Grant dateSep 6, 1988
Priority date
Expiry dateFeb 6, 2007

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC21D8/04
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

An r value of a hot-rolled steel sheet is enhanced by: a specific composition consisting of not more than 0.015 wt % of C, from 1.0 to 2.5 wt % of Mn, from 0.005 to 0.10 wt % of Al, from 0.01 to 0.06 wt % of Nb, from 0.01 to 0.1 wt % of Ti; and, controlled rolling, characterized by in the rough rolling, imparting, in a temperature range of from 980.degree. to 1100.degree. C., a heavy reduction of not less than 20% per pass to the steel sheet; completing a finishing rolling at from Ar.sub.3 to 930.degree. C. and maintaining a total reduction at a temperature of not more than Ar.sub.3 +150.degree. C. to not less than 90%; and, coiling at a temperature of from 600.degree. to 800.degree. C.

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