Method for producing steel sheet for cold rolling and method for producing cold-rolled steel sheet

Patent metadata

Field	Value
Publication number	US-2024216967-A1
Application number	US-202218558949-A
Country	US
Kind code	A1
Filing date	Apr 8, 2022
Priority date	May 7, 2021
Publication date	Jul 4, 2024
Grant date	—

Abstract

A method for manufacturing a steel sheet for cold rolling, including hot-rolling a slab so that an outlet temperature of a finishing rolling mill is 800° C. or higher and 940° C. or lower, cooling at least a portion of the hot-rolled steel sheet, at a water volume density of 100 L/min/m2 or more for 0.1 seconds or more, within 3.0 seconds after passing through a final stand of the finishing rolling mill and being sent out on a run-out table, and coiling, at a coiling temperature of 550° C. or higher, the cooled hot-rolled steel sheet.

First claim

1 . A method for manufacturing a steel sheet for cold rolling, the method comprising:
hot-rolling a slab having a chemical composition containing: C: 0.15% by mass or more and 0.25% by mass or less, Si: 0.8% by mass or more and 3.0% by mass or less, Mn: 1.8% by mass or more and 3.0% by mass or less, Ni, Cu, Cr, and Mo: 1.0% by mass or less (including 0% by mass), Ti, Nb, V: 1.0% by mass or less (including 0% by mass), and B: 0.01% by mass or less (including 0% by mass), so that an outlet temperature of a finishing rolling mill is 800° C. or higher and 940° C. or lower; cooling at least a portion of the hot-rolled steel sheet, at a water volume density of 100 L/min/m 2 or more for 0.1 seconds or more, within 3.0 seconds after passing through a final stand of the finishing rolling mill and being sent out on a run-out table; and coiling, at a coiling temperature of 550° C. or higher, the cooled hot-rolled steel sheet.

2 . The method for manufacturing a steel sheet for cold rolling according to claim 1 , wherein the slab further contains:
P: 0.1% by mass or less (including 0% by mass), S: 0.01% by mass or less (including 0% by mass), Al: 0.10% by mass or less (including 0% by mass), and N: 0.01% by mass or less (including 0% by mass).

3 . A method for manufacturing a cold-rolled steel sheet, comprising cold-rolling a steel sheet manufactured by the method according to claim 1 at a rolling rate of 30% to 80%.

Assignees

• Kobe Steel Ltd

Inventors

• Kitagawa Toma
• Murakami Toshio
• Teraoka Takashi
• Yoneda Takuma
• Harada Shun
• Nakayama Keita
• Ishitobi Katsuma
• Kobayashi Masanori
• Fukushima Koki

Classifications

• B21B2001/225

  by hot-rolling · CPC title

• B21B1/26 Primary

  by hot-rolling {, e.g. Steckel hot mill} · CPC title

• B21B45/0203

  Cooling · CPC title

• B21B3/00 Primary

  Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences {; Rolling of aluminium, copper, zinc or other non-ferrous metals}(altering special metallurgical properties of alloys, other than structure consolidation or mechanical properties resulting therefrom C21D, C22F) · CPC title

• C22C38/34

  with more than 1.5% by weight of silicon · CPC title