Manufacturing method of PC steel bar with excellent elongation and high temperature relaxation characteristics and PC steel bar with high temperature relaxation characteristics with high uniform extension and resistance ratio

摘要

The present invention quenched steel containing 160% by weight of C: 0.5-0.7%, Mn: 0.2-2.0%, 2.0% ≤Si + A1≤5.0% of Si and A1 at 160 ° C to 1300 ° C, and then tempering. By processing, high uniform elongation and low yield ratio of high temperature relaxation with a tensile strength of 1080 N / mm2 or more that can be manufactured by a conventional process without requiring a strain imparting process The present invention relates to a method of manufacturing a PC steel bar having excellent characteristics.