The welding structural steel and corrosion-proof mannered null mass is superior in resistance seawater corrosiveness of the ship ballast tank which uses

摘要

PROBLEM TO BE SOLVED: To provide steel for welded structure having excellent seawater corrosion resistance and also to provide a corrosion protection method for a ship ballast tank using the same.;SOLUTION: The steel is characterized in that: steel, which has a composition consisting of, by mass, 0.03 to 0.2% C, 0.01 to 2.5% Si, 0.01 to 2.0% Mn, ≤0.03% P, ≤0.03% S, 0.01 to 0.3% Al, one or more elements among Cu, Cr, Ni, Mo, W, Sb, Sn, Se and Pb, and the balance Fe with inevitable impurities, is used as a basis material; and a coating layer of 0.5 to 500μm thickness which is composed mainly of a metal having an immersion potential in seawater baser than that of the basis material is formed on the external surface of a part or the whole of the basis material. Further, in the corrosion protection method, a part or all of structural members inside the ship ballast tank are constituted of the above steel.;COPYRIGHT: (C)2007,JPO&INPIT