MANUFACTURE OF COLD ROLLED STEEL SHEET HAVING SUPERIOR BURNING HARDENABILITY AND PRESS FORMABILITY

Title:

MANUFACTURE OF COLD ROLLED STEEL SHEET HAVING SUPERIOR BURNING HARDENABILITY AND PRESS FORMABILITY

Document Type and Number:

Japanese Patent JPH01188627

Kind Code:

A

Abstract:

PURPOSE: To suppress surface roughening during press forming as well as to improve deep drawability and burning hardenability by hot rolling a low C steel having a specified compsn., specifying temp. conditions after finish rolling, and subjecting the resulting steel sheet to coiling, cold rolling and box annealing.

CONSTITUTION: When a steel consisting of, by weight, 0.002W0.02% C, ≤0.08% Si, ≤0.5% Mn, ≤0.1% P, ≤0.05% S, 0.01W0.1% sol. Al, 0.0015W0.012% N and the balance Fe is hot rolled, finish rolling is finished at the Ar3 point or above. The resulting steel sheet is cooled to (Ar3 point-30°C) or below at 80W400°C/sec cooling rate in the temp. range of the Ar3 point or above to Ar3 pointW(Ar3 point-30°C) and coiled at ≤550°C. The steel sheet is then cold rolled and box-annealed as usual.

Inventors:

KINO NOBUYUKI
TSUCHIYA HIROTSUGU
MATSUMURA GIICHI

Application Number:

JP1008788A

Publication Date:

July 27, 1989

Filing Date:

January 20, 1988

Export Citation:

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Assignee:

NIPPON STEEL CORP

International Classes:

C21D9/46; C21D8/02; C21D8/04; C22C38/00; C22C38/06; (IPC1-7): C21D8/02; C21D9/46; C22C38/00; C22C38/06

Attorney, Agent or Firm:

Yuji Miura

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