Steel sheet for crown cap, crown cap and method for producing steel sheet for crown cap

Patent metadata

Field	Value
Publication number	US-11459149-B2
Application number	US-201816631539-A
Country	US
Kind code	B2
Filing date	Jul 25, 2018
Priority date	Jul 31, 2017
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

A steel sheet for crown cap having excellent formability from which a crown cap having an excellent pressure resistance can be produced without an expensive soft liner even if the steel sheet is subjected to sheet metal thinning, the steel sheet having: a chemical composition containing, in mass %, C: more than 0.006% and 0.012% or less, Si: 0.02% or less, Mn: 0.10% or more and 0.60% or less, P: 0.020% or less, S: 0.020% or less, Al: 0.01% or more and 0.07% or less, and N: 0.0080% or more and 0.0200% or less, with the balance being Fe and inevitable impurities; and a percentage of a region of more than 0% and less than 20% at a position of ½ of a sheet thickness, the region having a dislocation density of 1×1014 m−2 or less.

First claim

The invention claimed is:

1. A steel sheet for crown cap having a chemical composition containing, in mass %,
C: more than 0.006% and 0.012% or less,
Si: 0.02% or less,
Mn: 0.10% or more and 0.60% or less,
P: 0.020% or less,
S: 0.020% or less,
Al: 0.01% or more and 0.07% or less, and
N: 0.0080% or more and 0.0200% or less, with the balance being Fe and inevitable impurities,
wherein the steel sheet has a percentage of a region of more than 0% and less than 20% at a position of ½ of a thickness of the steel sheet, the region having a dislocation density of 1×10 14 m −2 or less.

2. The steel sheet for crown cap according to claim 1 , wherein the thickness of the steel sheet is 0.20 mm or less.

3. A crown cap made of the steel sheet for crown cap according to claim 1 .

4. The crown cap according to claim 3 comprising a resin liner having an ultra-low loaded hardness of 0.70 or more.

5. A method for producing the steel sheet for crown cap according to claim 1 comprising:
hot rolling a steel slab having the chemical composition according to claim 1 , whereby the steel slab is reheated to a slab heating temperature of 1200° C. or higher and subjected to finish rolling to obtain a steel sheet, and then the steel sheet is coiled at a coiling temperature of 670° C. or lower;
after the hot rolling, pickling the steel sheet;
after the pickling, subjecting the steel sheet to primary cold rolling;
after the primary cold rolling, subjecting the steel sheet to continuous annealing at an annealing temperature of 750° C. or lower; and
after the continuous annealing, subjecting the steel sheet to secondary cold rolling in an apparatus comprising two or more stands, wherein
the secondary cold rolling has a rolling reduction of 10% or more and 30% or less and a rolling rate of 400 mpm or more on the exit side of a final stand.

6. A crown cap made of the steel sheet for crown cap according to claim 2 .

7. A method for producing the steel sheet for crown cap according to claim 2 comprising:
hot rolling a steel slab having the chemical composition according to claim 1 , whereby the steel slab is reheated to a slab heating temperature of 1200° C. or higher and subjected to finish rolling to obtain a steel sheet, and then the steel sheet is coiled at a coiling temperature of 670° C. or lower;
after the hot rolling, pickling the steel sheet;
after the pickling, subjecting the steel sheet to primary cold rolling;
after the primary cold rolling, subjecting the steel sheet to continuous annealing at an annealing temperature of 750° C. or lower; and
after the continuous annealing, subjecting the steel sheet to secondary cold rolling in an apparatus comprising two or more stands, wherein
the secondary cold rolling has a rolling reduction of 10% or more and 30% or less and a rolling rate of 400 mpm or more on the exit side of a final stand.

Assignees

• Jfe Steel Corp

Inventors

• Ueno Takashi
• Kariya Nobusuke
• Kojima Katsumi
• Yamamoto Yoshihide
• Katagiri Akihiro

Classifications

• C21D8/02 Primary

  during manufacturing of plates or strips (C21D8/12 takes precedence) · CPC title

• C23G1/00

  Cleaning or pickling metallic material with solutions or molten salts (with organic solvents C23G5/02) · CPC title

• C21D8/0236

  Cold rolling · CPC title

• C22C38/06

  containing aluminium · CPC title

• C22C38/001

  containing N · CPC title