Method of producing ferritic stainless steel sheet

Patent metadata

Field	Value
Publication number	US-10358689-B2
Application number	US-201715811383-A
Country	US
Kind code	B2
Filing date	Nov 13, 2017
Priority date	Feb 4, 2013
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

Ferritic stainless steel sheet which is excellent in ridging resistance which comprises, by mass %, Cr: 10 to 30%, Sn: 0.005 to 1%, C: 0.001 to 0.1%, N: 0.001 to 0.1%, Si: 0.01 to 3.0%, Mn: 0.01 to 3.0%, P: 0.005 to 0.1%, and S: 0.0001 to 0.01% and has a balance of Fe and unavoidable impurities and which has an X-ray diffraction strength in the {100}<012> orientation from a surface layer to t/4 (“t” is sheet thickness) of 2 or more.

First claim

The invention claimed is:

1. A method of producing a ferritic stainless steel sheet excellent in workability comprising, by mass %, Cr: 10 to 30%, Sn: 0.005 to 1%, C: 0.001 to 0.1%, N: 0.001 to 0.1%, Si: 0.01 to 3.0%, Mn: 0.01 to 3.0%, P: 0.005 to 0.1%, S: 0.0001 to 0.01% and a balance of Fe and unavoidable impurities,
wherein an X-ray diffraction strength in the {100}<012> orientation from a surface layer of the steel sheet to t/4 is 2 or more, wherein “t” represents the sheet thickness,
the method comprising the steps of:
heating a hot rolled steel sheet to 850° C. during annealing the steel sheet;
cooling the steel sheet down to 500° C. by a cooling speed of over 10° C./sec and less than 15° C./sec; and
cold rolling the steel sheet using rolls of a diameter of 150 mm or less by a reduction rate of 60% or more.

2. A method of producing a ferritic stainless steel sheet excellent in workability comprising, by mass %, Cr: 10 to 30%, Sn: 0.005 to 1%, C: 0.001 to 0.1%, N: 0.001 to 0.1%, Si: 0.01 to 3.0%, Mn: 0.01 to 3.0%, P: 0.005 to 0.1%, S: 0.0001 to 0.01%, and further comprising, by mass %, one or more of Ti: 0.005 to 0.5%, Nb: 0.005 to 0.5%, Zr: 0.005 to 0.5%, V: 0.01 to 0.5%, Ni: 0.01 to 1%, Mo: 0.1 to 3.0%, W: 0.1 to 3.0%, Cu: 0.1 to 3.0%, B: 0.0003 to 0.0100%, Al: 0.01 to 1.0%, Ca: 0.0001 to 0.003%, Mg: 0.0001 to 0.005%, Co: 0.001 to 0.5%, Sb: 0.005 to 0.3%, REM: 0.001 to 0.2%, and Ga: 0.0002 to 0.3% or less and a balance of Fe and unavoidable impurities,
wherein an X-ray diffraction strength in the {100}<012> orientation from a surface layer of the steel sheet to t/4 is 2 or more, wherein “t” represents the sheet thickness,
the method comprising the steps of:
heating a hot rolled steel sheet to 850° C. during annealing the steel sheet;
cooling the steel sheet down to 500° C. by a cooling speed of over 10° C./sec and less than 15° C./sec; and
cold rolling the steel sheet using rolls of a diameter of 150 mm or less by a reduction rate of 60% or more.

Assignees

• Nippon Steel & Sumikin Sst

Inventors

• Hamada Junichi
• Ishimaru Eiichiro

Classifications

• C22C38/60

  containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur · CPC title

• C22C38/40

  with nickel · CPC title

• C22C38/38

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

• C22C38/30

  with cobalt · CPC title

• C22C38/18

  containing chromium · CPC title