STEEL BAR FOR PRESTRESSED CONCRETE WITH IMPROVED FRACTURE ELONGATION OF SPOT WELDED PART

摘要

The present invention relates to a very small spot and only improved elongation at break of the welded portion of the steel bar for high-strength agent prestressed concrete rakse used in muscle tension of the high-strength concrete pile is required Orientation loss.; PC steel bar of the present invention, the base component of the material 0.25~0.40wt% C, Si 0.8~1.5wt%, Mn 0.60~2.0wt%, P + S is contained 0.04wt% or less, Ti here 0.01~0.05wt %, B 0.0005~0.0050wt%, Al 0.01~0.05wt% added or Ti 0.01~0.05wt%, B 0.0005~0.0050wt%, Al 0.01~0.05wt% and Cr 0.02~0.30wt% is added and the remaining portion Fe and inevitable as a composition consisting of impurity, on the other, while the same drive the material liners made of continuous composition is at least a heating tensile strength subjected to quenching, tempering treatment to the Ac3 point than 1420MPa, the high temperature re rakse Orientation lost more than 15% this represents a prestressed concrete steel bar for elongation at break, including spot weld is characterized in that at least 5%.; Steel material of the invention, the bending force applied to the process or file that tension to the elongation at break of, spot weld while maintaining a re-rakse Orientation properties at high temperatures when compared to conventional steels is much better to produce the PHC piles external force in the benefits are likely to be almost no break from such an advantage that can be made of PC steel rod having excellent ductility of the weld spot.