FERRITIC STAINLESS STEEL SHEET WHICH IS EXCELLENT IN WORKABILITY AND METHOD OF PRODUCTION OF SAME

• US 20150376732A1
• Filed: 02/04/2014
• Published: 12/31/2015
• Est. Priority Date: 02/04/2013
• Status: Abandoned Application

• Current Assignee: Nippon Steel & Sumikin Stainless Steel Corporation (Nippon Steel Corporation)
• Original Assignee: Nippon Steel & Sumikin Stainless Steel Corporation (Nippon Steel Corporation)
• Inventors: HAMADA, Junichi, ISHIMARU, Eiichiro
• Application Number:
  US14/765,535
• Publication Number:
  US 20150376732A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C21D 1/84 Controlled slow cooling cooling-beds for metal rolling B21B43/00
• CPC Class Codes: C21D 2211/004 Dispersions; Precipitations
• CPC Class Codes: C21D 2211/005 Ferrite
• CPC Class Codes: C21D 6/002 containing Cr C21D6/004 takes precedence
• CPC Class Codes: C21D 6/02 Hardening by precipitation
• CPC Class Codes: C21D 8/0205 of ferrous alloys
• CPC Class Codes: C21D 8/0236 Cold rolling
• CPC Class Codes: C21D 9/46 for sheet metals
• CPC Class Codes: C22C 38/00 Ferrous alloys, e.g. steel alloys cast-iron alloys C22C37/00
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• CPC Class Codes: C22C 38/004 Very low carbon steels, i.e. having a carbon content of less than 0,01%
• CPC Class Codes: C22C 38/005 containing rare earths, i.e. Sc, Y, Lanthanides
• CPC Class Codes: C22C 38/008 containing tin
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/18 containing chromium
• CPC Class Codes: C22C 38/20 with copper
• CPC Class Codes: C22C 38/22 with molybdenum or tungsten
• CPC Class Codes: C22C 38/24 : with vanadium
• CPC Class Codes: C22C 38/26 : with niobium or tantalum
• CPC Class Codes: C22C 38/28 : with titanium or zirconium
• CPC Class Codes: C22C 38/30 : with cobalt
• CPC Class Codes: C22C 38/32 : with boron
• CPC Class Codes: C22C 38/38 : with more than 1.5% by weight of manganese
• CPC Class Codes: C22C 38/40 : with nickel
• CPC Class Codes: C22C 38/42 : with copper
• CPC Class Codes: C22C 38/44 : with molybdenum or tungsten
• CPC Class Codes: C22C 38/46 : with vanadium
• CPC Class Codes: C22C 38/48 : with niobium or tantalum
• CPC Class Codes: C22C 38/50 : with titanium or zirconium
• CPC Class Codes: C22C 38/52 : with cobalt
• CPC Class Codes: C22C 38/54 : with boron
• CPC Class Codes: C22C 38/58 : with more than 1.5% by weight of manganese
• CPC Class Codes: C22C 38/60 : containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur

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.

Claims

1. 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.

2. The ferritic stainless steel sheet excellent in workability according to claim 1 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.

3. A method of producing ferritic stainless steel sheet excellent in workability according to claim 1, 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 50°

C./sec or less; and

cold rolling the steel sheet using rolls of a diameter of 150 mm or less by a reduction rate of 60% or more.

4. A method of producing ferritic stainless steel sheet excellent in workability according to claim 2, 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 50°

C./sec or less; and

cold rolling the steel sheet using rolls of a diameter of 150 mm or less by a reduction rate of 60% or more.