Ferritic stainless steel plate which has excellent ridging resistance and method of production of same

Patent metadata

Field	Value
Publication number	US-9771640-B2
Application number	US-201214126083-A
Country	US
Kind code	B2
Filing date	Jun 18, 2012
Priority date	Jun 16, 2011
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A ferritic stainless steel sheet having ridging resistance contains, by mass, 0.025 to 0.30% C, 0.01 to 1.00% Si, 0.01 to 2.00% Mn, 0.050% or less P, 0.020% or less S, 11.0 to 22.0% Cr, and 0.022 to 0.10% N. In addition, Ap, which is defined as 420C+470N+23Ni+9Cu+7Mn−11.5(Cr+Si)−12Mo−52Al−47Nb−49Ti+189 wherein each of Sn, C, N, Ni, Cu, Mn, Cr, Si, Mo, Al, Nb, and Ti denotes the content of the element, satisfies 10≦Ap≦70. Furthermore, a content of Sn satisfies 0.060≦Sn≦0.634−0.0082Ap. Residual ingredients are Fe and unavoidable impurities, and a metal structure of the steel sheet is a ferrite single phase. The ferritic stainless steel sheet has a ridging height of less than 6 μm. This ferritic stainless steel sheet improves the corrosion resistance and rust resistance of Cr-containing ferritic stainless steel as well as the ridging resistance.

First claim

The invention claimed is:

1. A ferritic stainless steel sheet which has ridging resistance, comprising, by mass,
C: 0.025 to 0.30%,
Si: 0.01 to 1.00%,
Mn: 0.01 to 2.00%,
P: 0.050% or less,
S: 0.020% or less,
Cr: 11.0 to 22.0%,
N: 0.022 to 0.10%,
Mo: 0.3% or less,
wherein Ap which is defined by the following (formula 3) satisfies the following (formula 2), a content of Sn satisfies the following (formula 1), residual ingredients are Fe and unavoidable impurities, and a metal structure of the steel sheet is a ferrite single phase,
0.060≦Sn≦0.634−0.0082 Ap   (formula 1)

10≦ Ap≦ 70  (formula 2)

Ap= 420C+470N+23Ni+9Cu+7Mn−11.5(Cr+Si)−12Mo−52Al−47Nb−49Ti+189  (formula 3)

wherein, each of Sn, C, N, Ni, Cu, Mn, Cr, Si, Mo, Al, Nb, and Ti denotes the content of the element, and
wherein the ferritic stainless steel sheet has a ridging height of less than 6 μm.

2. The ferritic stainless steel sheet which has ridging resistance according to claim 1 , further comprising, by mass, one or more elements of
Al: 0.0001 to 1.0%,
Nb: 0.30% or less,
Ti: 0.30% or less
Ni: 1.0% or less,
Cu: 1.0% or less,
V: 1.0% or less,
Co: 0.5% or less, and
Zr: 0.5% or less.

3. The ferritic stainless steel sheet which has ridging resistance according to any one of claim 1 or 2 , further comprising, by mass, one or more elements of
B: 0.005% or less,
Mg: 0.005% or less,
Ca: 0.005% or less,
Y: 0.1% or less,
Hf: 0.1% or less, and
a REM: 0.1% or less.

Assignees

• Hatano Masaharu
• Ishimaru Eiichiro
• Takahashi Akihiko
• Kimura Ken
• Teraoka Shinichi
• Nippon Steel & Sumikin Sst

Inventors

• Hatano Masaharu
• Ishimaru Eiichiro
• Takahashi Akihiko
• Kimura Ken
• Teraoka Shinichi

Classifications

• C22C38/28

  with titanium or zirconium · CPC title

• B21B1/38

  for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, {pack rolling}(B21B1/40 takes precedence; folding sheets before, or separating layers after, rolling B21B47/00) · CPC title

• C22C38/26

  with niobium or tantalum · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C22C38/54 Primary

  with boron · CPC title