STEEL MATERIAL SHIP BALLAST TANK AND HOLD FORMED USING SAID STEEL MATERIAL AND SHIP EQUIPPED WITH SAID BALLAST TANK OR HOLD

摘要

The steel material has a predetermined chemical composition, has a soft texture and a hard texture, and has an Sn concentration ratio of 1.2 or more and 6.0 or less, which is a ratio of the Sn concentration in the hard texture to the Sn concentration in the soft texture.