Patent ID: 7854808
Filing Date: 2010-12-21
Classification: C21D,C22C

Abstract:
1. A steel sheet for vitreous enameling excellent in workability, aging properties and enameling properties, the steel sheet comprising: no more than 0.0025 mass percent carbon; no more than 0.010 mass percent silicon; from 0.1 to 0.5 mass percent manganese; 0.0005 to 0.0033 mass percent nitrogen; from 0.60 times the amount of nitrogen to 0.0060 mass percent boron; from 10 times the difference between the amount of boron and 11/14 times the amount of nitrogen, 10×(B−11/14×N), to 0.030 mass percent phosphorous; no more than 0.030 mass percent sulfur; no more than 0.010 mass percent aluminum; 0.005 to 0.0450 mass percent oxygen; and a balance of Fe and unavoidable impurities, wherein the steel sheet contains simple or compound nitrides, having a diameter of 0.02 to 0.50 μm, containing boron or aluminum, and having an average diameter of at least 0.080 μm, and the proportion of the number of the nitrides of 0.050 pm or smaller in diameter to the total number of the nitrides is 10 percent or less, wherein the ratio of the amount of nitrogen in the steel sheet existing as boron nitride, BN, to the amount of nitrogen in the steel sheet existing as aluminum nitride AlN, the steel sheet further comprises a nickel plating on the steel sheet in an amount of about 0.01 to 2 g/m