Patent ID: 8293038

Claim:
A method for producing a ferritic stainless steel sheet having an average r-value of 2.0 or more, an ridging height of 5 μm or less and an elongation of 35% or more, 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, 0.0002 to 0.0050% Mg, and further contains Al and/or Ca, with a balance consisting of Fe and unavoidable impurities, and the value of Σ defined by the expression <1> is 0.70 or less, Σ=0.9[Si]+8.6[P]+2[Ti]+0.5[Mn]−0.5 <1>; wherein [Si], [P], [Ti], and [Mn] represents contents of Si, P, Ti and Mn in said steel, respectively, and the average composition of the Mg containing oxides dispersing in said casting satisfies the expressions <2> and <3>, 17.4(Al 2 O 3 )+3.9(MgO)+0.3(MgAl 2 O 4 )+18.7(CaO)≦500 <2>, (Al 2 O 3 )+(MgO)+(MgAl 2 O 4 )+(CaO)≧95 <3>, wherein the chemical components in the parentheses mean mol % of the relevant chemical components, respectively, said method comprising hot rolling the casting by a method comprising heating said casting to temperature T1 within the range defined by the expression <4>, subjecting said heated casting to rough rolling of plural passes, and finishing rolling of plural passes at a temperature of 850° C. or lower; coiling said hot-rolled steel sheet at a temperature of 700° C. or lower; annealing said hot-rolled steel sheet at a heating temperature T2 in the range defined by the expression <5>; cold rolling said annealed steel sheet; and subsequently annealing said cold-rolled steel sheet at a heating temperature T3 in the range defined by the expression <6>, 1,000≦T1(° C.)≦−100−8,714/(log([Ti]×[C] 0.5 ×[S] 0.5 )−3.4) <4>, −5,457/(log([T1]×[C])−2.6)≦T2(° C.)≦1,000 <5>, −100−5,457/(log([Ti]×[C])−2.6)≦T3(° C.)≦−5,457/(log([Ti]×[C])−2.6) <6> wherein [Ti], [C], and [S] represents contents of Ti, C, and S in said steel, respectively.