PC STEEL WIRE HAVING SATISFACTORY DELAYED FRACTURE RESISTANCE, PRODUCTION METHOD THEREFOR, AND PC STRANDED WIRE

摘要

PPROBLEM TO BE SOLVED: To provide a PC (Prestress Concrete) steel rod which is used for a concrete pole, a concrete pile or the like, further, to provide a PC steel wire which is also effective for a material requiring delayed fracture resistance such as PWS (Parallel Wire Strand) for bridges, to provide a production method therefor, and to provide a PC stranded wire. PSOLUTION: The PC steel wire having satisfactory delayed fracture resistance comprises, by mass, 0.6 to 1.3% C, and has a wire diameter of 2.9 to 9 mm. At least, in the surface layer from the steel surface layer to 2.5% of the wire diameter, the residual stress in the longitudinal direction is the compressive stress. Also, the residual stress in the longitudinal direction of the outermost surface layer part is the compressive stress of 150 MPa. The PC steel wire has a structure consisting essentially of worked pearlite, has YS (0.2% Yield Strength) of 1,000 MPa, and TS (Tensile Strength) of 1,200 MPa. The PC stranded wire is obtained by stranding the steel wire. PCOPYRIGHT: (C)2004,JPO