US 2008/0142123 A1 · Ferritic stainless steel casting and sheet and method for producing the same

Abstract

The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions <2> and <3>, 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)≦500<2>, (Al2O3)+(MgO)+(MgAl2O4)+(CaO)≧95<3>.

Claims5

Dependent claims

1-6. (canceled)

A method for producing a ferritic stainless steel sheet comprising using a casting wherein:

said casting contains, in mass, 0.001 to 0.010% C, 0.01 to 0.30% Si, 0.01 to 0.30% Mn, 0.01 to 0.04% P, 0.0010 to 0.0100% S, 10 to 20% Cr, 0.001 to 0.020% N, 0.05 to 0.30% Ti, and 0.0002 to 0.0050% Mg, with the balance consisting of Fe and unavoidable impurities, and the value of Σdefined by the expression <1> is 0.70 or less,
Σ=0.9Si+8.6P+2 Ti+0.5 Mn−0.5 <1>;
and the average composition of the Mg containing oxides dispersing in said casting satisfies the expressions <2> and <3>,
17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)≦500 <2>,
(Al2O3)+(MgO)+(MgAl2O4)+(CaO)≧95 <3>,
wherein the chemical components in the parentheses mean mol % of the relevant chemical components, respectively.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application

11/985,296Filed 13 Nov 2007

Priority

JP 2002-08770327 Mar 2002

Published

19 Jun 2008

Term ends

Not estimatedThe source records don’t support an estimate.

Classification16 codes

C22C 38/002
Ferrous alloys, e.g. steel alloys: containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
C21C 5/005
Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel: manufacture of stainless steel
C21C 7/0006
Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00: adding metallic additives
C21C 7/005
Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00: using exothermic reaction compositions

Ferritic stainless steel casting and sheet and method for producing the same

Life of this patent

Ferritic stainless steel casting and sheet and method for producing the same

Life of this patent

Abstract

Claims5