| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel sheet pile having a high strength joint which shows yield strength of 510 MPa or higher and total elongation of 17% or higher when tested by using a round bar test piece for the tensile test specified in JIS14A, as tensile properties of the joint. SOLUTION: This steel sheet pile has a composition comprising 0.02-0.08% C, 0.01-0.50% Si, 0.5-1.8% Mn, 0.01% or less P, 0.01 or less S, 0.05-0.50% Mo, 0.005-0.04% Ti, 0.01-0.07% Al, further at least one of 0.005-0.05% Nb and 0.005-0.10% V (by mass% heretofore) and the balance substantially Fe; has a carbon equivalent (Ceq.) of less than 0.40%, which is shown in the expression: Ceq.=C+Mn/6+Si/24+Ni/40+Cr/5+Mo/4+V/14; has C/(Mo+Ti+Nb+V) of 0.5-3.0 by atom.%, which is a ratio of C quantity of the total quantity of Mo, Ti, Nb and V; and has fine precipitates containing Ti and Mo with the sizes of less than 10 nm dispersed in a matrix substantially consisting of ferrite. COPYRIGHT: (C)2004,JPO
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