| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-strength steel sheet which has a strength of an API X65 grade or higher, superior resistance to HIC (hydrogen induced cracking) which occurs in a central segregation part and the vicinities of the surface or from inclusions, and superior toughness of welds. SOLUTION: The high-strength steel sheet superior in HIC resistance comprises, by mass%, 0.02-0.08% C, 0.01-0.50% Si, 0.5-1.8% Mn, 0.01% or less P, 0.002% or less S, 0.05-1.0% W, 0.005-0.04% Ti, 0.01-0.07% Al, 0.005-0.08% Nb and/or 0.005-0.10% V, the balance substantially Fe, and C/(W+Ti+Nb+V) of 0.5-3.0 by atom.%, which is a ratio of C quantity to the total quantity of W, Ti, Nb, and V; and has metallographic structure consisting substantially of a single phase of ferrite, and of dispersed precipitates containing Ti and W. COPYRIGHT: (C)2004,JPO
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