STEEL FOR BALLAST TANK HAVING EXCELLENT CORROSION RESISTANCE, AND SHIP HAVING BALLAST TANK MADE THEREFROM

摘要

A steel material for ballast tank having excellent corrosion resistance and a ship having a ballast tank made of the same are provided to obtain a steel material for ship with superior corrosion resistance by adjusting the chemical composition and the metal organization and/or nonmetal inclusion properly. A steel material for ballast tank having excellent corrosion resistance comprises C 0.01~0.30%, Si 0.01~2.0%, Mn 0.01~2.0%, P: 0.01% or less, S 0.0005~0.005%, Al 0.005~0.10%, Cu 0.1~1.0%, Ni 0.01~1.0%, Cr 0.01~0.5%, Ca 0.0001~0.005%, Ti 0.005~0.20%, and the rest Fe and inevitable impurities. The steel material has an organization in which ferrite is 50% or greater and bainite or martensite is less than 30% as to area rate. In the steel material, the average particle diameter of sulfide based inclusion is 0.5~10mum.