Stainless steel for metal foils, stainless steel foil, and methods for producing them

Patent metadata

Field	Value
Publication number	US-2023077573-A1
Application number	US-202117800924-A
Country	US
Kind code	A1
Filing date	Feb 24, 2021
Priority date	Feb 27, 2020
Publication date	Mar 16, 2023
Grant date	—

Abstract

The stainless steel for metal foils includes, in mass %, 0.0001% or more and 0.15% or less of C, 0.30% or more and 2.0% or less of Si, 0.1% or more and 15% or less of Mn, 0.040% or less of P, 5% or more and 30% or less of Ni, 0.0001% or more and 0.01% or less of S, 16% or more and 25% or less of Cr, 5% or less of Mo, 0.005% or less of Al, 0.0030% or less of Ca, 0.0010% or less of Mg, 0.0010% or more and 0.0060% or less of O, and 0.0001% or more and 0.5% or less of N. The number of inclusions with a maximum equivalent circle diameter of 5 μm or more is 0.5 inclusions/mm2 or less in a thickness of 0.010 mm or more and 0.2 mm or less.

First claim

1 . A stainless steel for metal foils, comprising:
C: 0.0001 mass % or more and 0.15 mass % or less, Si: 0.30 mass % or more and 2.0 mass % or less, Mn: 0.1 mass % or more and 15 mass % or less, P: 0.040 mass % or less, Ni: 5 mass % or more and 30 mass % or less, S: 0.0001 mass % or more and 0.01 mass % or less, Cr: 16 mass % or more and 25 mass % or less, Mo: 5 mass % or less, Al: 0.005 mass % or less, Ca: 0.0030 mass % or less, Mg: 0.0010 mass % or less, O: 0.0010 mass % or more and 0.0060 mass % or less, and N: 0.0001 mass % or more and 0.5 mass % or less, and a remainder comprising Fe and inevitable impurities, wherein the number of inclusions with a maximum equivalent circle diameter of 5 mm or more is 0.5 inclusions/mm 2 or less in a thickness of 0.010 mm or more and 0.2 mm or less.

2 . The stainless steel for metal foils according to claim 1 , which does not comprise a first inclusion with an equivalent circle diameter of 5 mm or more, having average composition of MnO: 10 mass % or more, Cr 2 O 3 +Al 2 O 3 : 30 mass % or more, and CaO: 10 mass % or less, and a second inclusion with an equivalent circle diameter of 5 mm or more, having average composition of MgO: 10 mass % or more, and Al 2 O 3 : 20 mass % or more.

3 . The stainless steel for metal foils according to claim 1 , further comprising at least any one of Cu: 0.1 mass % or more and 4.0 mass % or less, REM: 0.00001 mass % or more and 0.0030 mass % or less, B: 0.0001 mass % or more and 0.0050 mass % or less, Ti: 0.01 mass % or more and 0.50 mass % or less, Nb: 0.01 mass % or more and 0.50 mass % or less, V: 0.01 mass % or more and 1.00 mass % or less, W: 0.01 mass % or more and 1.00 mass % or less, Co: 0.01 mass % or more and 1.00 mass % or less, and Sn: 0.01 mass % or more and 1.00 mass % or less.

4 . A stainless steel foil, comprising:
a thickness of 0.010 mm or more and 0.2 mm or less, and comprising component composition of
C: 0.0001 mass % or more and 0.15 mass % or less,
Si: 0.30 mass % or more and 2.0 mass % or less,
Mn: 0.1 mass % or more and 15 mass % or less,
P: 0.040 mass % or less,
Ni: 5 mass % or more and 30 mass % or less,
S: 0.0001 mass % or more and 0.01 mass % or less,
Cr: 16 mass % or more and 25 mass % or less,
Mo: 5 mass % or less, Al: 0.005 mass % or less,
Ca: 0.0030 mass % or less,
Mg: 0.0010 mass % or less,
O: 0.0010 mass % or more and 0.0060 mass % or less,
N: 0.0001 mass % or more and 0.5 mass % or less, and
a remainder comprising Fe and inevitable impurities, wherein the number of inclusions with a maximum equivalent circle diameter of 5 mm or more is 0.5 inclusions/mm 2 or less.

5 . The stainless steel foil according to claim 4 , further containing at least any one of Cu: 0.1 mass % or more and 4.0 mass % or less, REM: 0.00001 mass % or more and 0.0030 mass % or less, B: 0.0001 mass % or more and 0.0050 mass % or less, Ti: 0.01 mass % or more and 0.50 mass % or less, Nb: 0.01 mass % or more and 0.50 mass % or less, V: 0.01 mass % or more and 1.00 mass % or less, W: 0.01 mass % or more and 1.00 mass % or less, Co: 0.01 mass % or more and 1.00 mass % or less, and Sn: 0.01 mass % or more and 1.00 mass % or less.

6 . A method for producing a stainless steel for metal foils to produce the stainless steel for metal foils according to claim 1 ,
the method comprising a refining step of performing refining in VOD or AOD, wherein slag composition is, in mass % ratio, CaO/SiO 2 : 1.1 or more and 1.7 or less, Al 2 O 3 : 4.0 mass % or less, and MgO: 10.0 mass % or less by adjusting Al and Al 2 O 3 contained in a raw material or a ladle, carrying out deoxidation using a Fe—Si alloy or metal Si, and also adding CaO or SiO 2 in the refining step, and moreover stirring molten steel at a stirring power of 50 W/ton or more for 5 minutes or more after adding a refining slag material and an alloy material.

7 . A method for producing a stainless steel foil to produce the stainless steel foil according to claim 4 ,
the method comprising a refining step of performing refining in VOD or AOD, wherein slag composition is, in mass % ratio, CaO/SiO 2 : 1.1 or more and 1.7 or less, Al 2 O 3 : 4.0 mass % or less, and MgO: 10.0 mass % or less by adjusting Al and Al 2 O 3 contained in a raw material or a ladle, carrying out deoxidation using a Fe—Si alloy or metal Si, and also adding CaO or SiO 2 in the refining step, and moreover stirring molten steel at a stirring power of 50 W/ton or more for 5 minutes or more after adding a refining slag material and an alloy material.

8 . The stainless steel for metal foils according to claim 2 , further comprising at least any one of Cu: 0.1 mass % or more and 4.0 mass % or less, REM: 0.00001 mass % or more and 0.0030 mass % or less, B: 0.0001 mass % or more and 0.0050 mass % or less, Ti: 0.01 mass % or more and 0.50 mass % or less, Nb: 0.01 mass % or more and 0.50 mass % or less, V: 0.01 mass % or more and 1.00 mass % or less, W: 0.01 mass % or more and 1.00 mass % or less, Co: 0.01 mass % or more and 1.00 mass % or less, and Sn: 0.01 mass % or more and 1.00 mass % or less.

9 . A method for producing a stainless steel for metal foils to produce the stainless steel for metal foils according to claim 2 ,
the method comprising a refining step of performing refining in VOD or AOD, wherein slag composition is, in mass % ratio, CaO/SiO 2 : 1.1 or more and 1.7 or less, Al 2 O 3 : 4.0 mass % or less, and MgO: 10.0 mass % or less by adjusting Al and Al 2 O 3 contained in a raw material or a ladle, carrying out deoxidation using a Fe—Si alloy or metal Si, and also adding CaO or SiO 2 in the refining step, and moreover stirring molten steel at a stirring power of 50 W/ton or more for 5 minutes or more after adding a refining slag material and an alloy material.

10 . A method for producing a stainless steel for metal foils to produce the stainless steel for metal foils according to claim 3 ,
the method comprising a refining step of performing refining in VOD or AOD, wherein slag composition is, in mass % ratio, CaO/SiO 2 : 1.1 or more and 1.7 or less, Al 2 O 3 : 4.0 mass % or less, and MgO: 10.0 mass % or less by adjusting Al and Al 2 O 3 contained in a raw material or a ladle, carrying out deoxidation using a Fe—Si alloy or metal Si, and also adding CaO or SiO 2 in the refining step, and moreover stirring molten steel at a stirring power of 50 W/ton or more for 5 minutes or more after adding a refining slag material and an alloy material.

11 . A method for producing a stainless steel for metal foils to produce the stainless steel for metal foils according to claim 8 ,
the method comprising a refining step of performing refining in VOD or AOD, wherein slag composition is, in mass % ratio, CaO/SiO 2 : 1.1 or more and 1.7 or less, Al 2 O 3 : 4.0 mass % or less, and MgO: 10.0 mass % or less by adjusting Al and Al 2 O 3 contained in a raw material or a ladle, carrying out deoxidation using a Fe—Si alloy or metal Si, and also adding CaO or SiO 2 in the refining step, and moreover stirring molten steel at a stirring power of 50 W/ton or more for 5 minutes or more after adding a refining slag material and an alloy material.

12 . A method for producing a stainless steel foil to produce the stainless steel foil according to claim 5 ,
the method comprising a refining step of performing refining in VOD or AOD, wherein slag composition is, in mass % ratio, CaO/SiO 2 : 1.1 or more and 1.7 or less, Al 2 O 3 : 4.0 mass % or less, and MgO: 10.0 mass % or less by adjusting Al and Al 2 O 3 contained in a raw material or a ladle, carrying out deoxidation using a Fe—Si alloy or metal Si, and also adding CaO or SiO 2 in the refining

Assignees

• Nippon Steel Stainless Steel Corp

Inventors

• Sakaizawa Yuto
• Shibata Tooru
• Kikuchi Shin
• Fukumoto Shigeo

Classifications

• C21D8/02

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

• C22C33/06

  using master alloys · CPC title

• C22C33/04

  by melting · CPC title

• C21D8/0273

  Final recrystallisation annealing · CPC title

• C21D8/0226

  Hot rolling · CPC title