METHOD OF MANUFACTURING STEEL REINFORCEMENTS FOR CONCRETE

摘要

The invention relates to the prodn. of concrete reinforcements of steel, with a yield strength of 400-600 mPa and an elongation of at least 14%, by rapidly cooling steel rod during or immediately after rolling. The mean heat fluy density H (in MW/sq.m.) between 800 and 600deg.C and the cooling time t(in sec.) are controlled so that H.t is less than 0.82d+0.6 but greater than 0.45d-0.4 and that log H is greater than or equal to -0.9641 ogd+2.098 (where d is the dia. of the rod in mm). The volume of the surface martensite/bainite zone and the degree of autotempering are controlled to give the required combination of strength and ductility.