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

摘要

This steel material contains given chemical components, has a flexible structure and a rigid structure, and has an Sn concentration ratio, which is the ratio of the Sn concentration in the rigid structure to the Sn concentration in the flexible structure, of 1.2 or higher but less than 6.0.