The high intensity welding structural steel and the production mannered null mass which are superior in super full house thermal weld

摘要

PROBLEM TO BE SOLVED: To provide steel for high strength welded structure which has excellent toughness in an ultrahigh heat input weld part HAZ (heat affected zone), and to provide its production method.;SOLUTION: The high strength steel for welded structure having the excellent toughness in the ultrahigh heat input weld part HAZ has a composition comprising, by mass, 0.01 to 0.20% C, 0.02 to 0.50% Si, 0.3 to 2.0% Mn, ≤0.03% P, 0.0001 to 0.030% S, 0.005 to 0.50% V, 0.0005 to 0.050% Al, and 0.003 to 0.050% Ti, and the balance iron with inevitable impurities, and further simultaneously comprising Mg and Ca, and in which the total lies in the range of 0.0003 to 0.010%.;COPYRIGHT: (C)2005,JPO&NCIPI