Patent ID: 10011888

Abstract:
A cold-rolled steel sheet for vitreous enameling has a predetermined chemical composition, in which a number density of Fe—Mn—Nb-based composite oxides having a diameter of 0.2 μm to 10 μm is 2×102 particle/mm2 to 1×104 particle/mm2; a fatigue limit ratio is higher than 0.42 after performing a heat treatment with an applied tensile strain of 10% at a heating temperature of 830° C. for a holding time of 5 minutes; voids are formed between the metallographic structure and the Fe—Mn—Nb-based composite oxides, and an equivalent circle diameter of the voids is 0.1 μm to 0.6 μm; and when each of the voids is approximated as a triangle and a long side of the triangle is set as a base, a value obtained by dividing a length of the base by a height of the triangle is 1.0 to 15.