| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high tensile strength steel plate in which excellent HAZ toughness can be secured when being subjected to high heat input welding. <P>SOLUTION: The high tensile strength steel plate having excellent toughness in the high heat input weld heat-affected zone has a composition comprising, by mass, 0.02 to 0.05% C, 0.05 to 0.20% Si, 1.0 to 2.5% Mn,≤0.02% (exclusive of 0%) P,≤0.005% (exclusive of 0%) S, 0.01 to 0.05% Al, 0.2 to 2.0% Ni, 0.5 to 2.0% Cr, 0.005 to 0.025% Ti and 0.004 to 0.010% N, and further satisfying the inequality of 2.3≤(Mn+0.7×Ni+Cr)≤3.7 and the inequality of [Cr/(Mn+0.7×Ni)]≥0.3, and the balance iron with inevitable impurities; wherein, Mn, Ni and Cr denote the contents (mass%) of the respective elements. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
