| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive corrosion-resistant steel material for a ship ballast tank having excellent corrosion resistance, which exhibits corrosion resistance even under a seawater corrosive environment such as a ship ballast tank, and in which the extension of a period to paint refinishing is made possible, and therefore, the reduction in the operation of paint refinishing can be achieved, and a method for producing the same.SOLUTION: The corrosion-resistant steel material for a ship ballast tank is obtained by heating a steel stock having a composition comprising, by mass, 0.03 to 0.20% C, 0.05 to 0.50% Si, 0.7 to 2.0% Mn, ≤0.035% P, ≤0.01% S, ≤0.10% Al, 0.02 to 0.2% Sn, 0.003 to 0.03% Nb, 0.005 to 0.030% Ti and 0.0010 to 0.010% N, and in which the contents of Cu, Ni and Cr are controlled to <0.20%, <0.20% and <0.20%, respectively, and the balance Fe with inevitable impurities at 1,000 to 1,350°C, thereafter finishing rolling in the temperature range of 600 to <800°C, and performing cooling. |
