Steel sheet for aerosol can bottom having high pressure resistance and excellent workability and method for producing same

Patent metadata

Field	Value
Publication number	US-9506131-B2
Application number	US-201214005126-A
Country	US
Kind code	B2
Filing date	Mar 15, 2012
Priority date	Mar 17, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A steel sheet containing C: 0.02% or more and 0.10% or less, Si: 0.01% or more and 0.5% or less, P: 0.001% or more and 0.100% or less, S: 0.001% or more and 0.020% or less, N: 0.007% or more and 0.025% or less, Al: 0.01% or more and {−4.2×N (%)+0.11}% or less, Mnf: 0.10% or more and less than 0.30% where Mnf is defined by equation Mnf=Mn−1.71×S, and the balance being Fe and inevitable impurities, in which the steel sheet has a thickness of 0.35 (mm) or less, the product of the lower yield point (N/mm 2 ) of the steel sheet and the thickness (mm) is 160 (N/mm) or less, and the product of the upper yield point (N/mm 2 ) of the steel sheet is 52.0 (N) or more.

First claim

The invention claimed is:

1. A steel sheet for the bottom of aerosol cans with high resistance to pressure and high formability, the steel sheet having a chemical composition containing, by mass %, C: 0.02% or more and 0.10% or less, Si: 0.01% or more and 0.5% or less, P: 0.001% or more and 0.100% or less, S: 0.001% or more and 0.020% or less, N: 0.007% or more and 0.025% or less, Al: 0.01% or more and {−4.2×N (%)+0.11}% or less and {3.0×N (%)}% or less, and Nf is 0.65 or more where Nf is defined by equation Nf={N−N as AlN}/N, where N in the equation denotes the N content (mass %) in the steel and N as AlN denotes the content (mass %) of N which is present in the steel in the form of AlN, Mnf: 0.10% or more and less than 0.30% where Mnf is defined by equation Mnf=Mn−1.71×S, where Mn and S in the equation respectively denote the contents (mass %) of Mn and S in the steel, and the balance being Fe and inevitable impurities,
wherein the steel sheet has a thickness of 0.35 mm or less, has a product of a lower yield point (N/mm 2 ) of the steel sheet and the thickness (mm) that is 160 (N/mm) or less, and has a product of a upper yield point (N/mm 2 ) of the steel sheet which is observed after performing an aging treatment at room temperature under conditions of a temperature of 25° C. and a duration of 10 days after giving a tensile prestrain of 10% to the steel sheet and a square of the thickness (mm) that is 52.0 (N) or more.

2. A method for manufacturing a steel sheet for the bottom of aerosol cans with high resistance to pressure and high formability, the method comprising:
producing molten steel having a chemical composition containing, by mass %, C: 0.02% or more and 0.10% or less, Si: 0.01% or more and 0.5% or less, P: 0.001% or more and 0.100% or less, S: 0.001% or more and 0.020% or less, N: 0.007% or more and 0.025% or less, Al: 0.01% or more and {−4.2×N (%)+0.11}% or less and {3.0×N (%)}% or less, Mnf: 0.10% or more and less than 0.30% where Mnf is defined by equation Mnf=Mn−1.71×S, where Mn and S in the equation respectively denote the contents (mass %) of Mn and S in the steel, and the balance being Fe and inevitable impurities,
casting the steel into a slab using a continuous casting method,
reheating the slab up to a temperature of 1150° C. or higher,
hot-rolling the slab under a condition of a coiling temperature of lower than 620° C.,
performing pickling, cold-rolling and then recrystallization annealing, and
performing temper rolling under a condition of an elongation of less than 3%,
wherein the steel sheet is capable of strain aging at room temperature.

3. The method for manufacturing a steel sheet for the bottom of aerosol cans with high resistance to pressure and high formability according to claim 2 , wherein the steel sheet has the chemical composition containing, by mass %, and Nf is 0.65 or more where Nf is defined by equation Nf={N−N as AlN}/N, where N in the equation denotes the N content (mass %) in the steel and N as AlN denotes the content (mass %) of N which is present in the steel in the form of AlN.

4. The method of claim 2 , wherein the aging treatment is at a room temperature of 25° C.

Assignees

• Kojima Katsumi
• Tanaka Takumi
• Suto Mikito
• Tada Masaki
• Tobiyama Yoichi
• Jfe Steel Corp

Inventors

• Kojima Katsumi
• Tanaka Takumi
• Suto Mikito
• Tada Masaki
• Tobiyama Yoichi

Classifications

• C21D8/02

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

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• B65D83/38

  Details of the container body (pressure relief devices B65D83/70) · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title

• C22C38/001

  containing N · CPC title