The high intensity welding structural steel and the production mannered null mass which are superior in low temperature tenacity of full house thermal

摘要

PROBLEM TO BE SOLVED: To provide high strength steel for welded structures which has excellent low temperature toughness in a high heat input weld part HAZ (heat affected zone), and to provide its production method.;SOLUTION: The high strength steel for welded structures having excellent low temperature toughness in the high heat input weld part HAZ has a composition comprising, by mass, 0.03 to 0.14% C, 0.02 to 0.50% Si, 0.3 to 2.0% Mn, ≤0.02% P, 0.0001 to 0.010% S, 0.0005 to 0.05% Al, 0.003 to 0.050% Ti, 0.0001 to 0.0025% B, and ≤0.05% O, and the balance iron with inevitable impurities, and further comprising one or more kinds of metals selected from 0.0001 to 0.0050% Mg and 0.0001 to 0.0050% Ca, and in which the total content does not exceed 0.0050%.;COPYRIGHT: (C)2005,JPO&NCIPI