HIGH STRENGTH STEEL ROD OF LARGE GAGE

摘要

This invention relates to a novel high strength steel rod of a large gage, which is made of a high carbon steel containing, by weight percent, from 0.65 to 0.90% carbon and from 0.15 to 1.5% chromium capable of wire drawing without subsequent heat treatment and has a diameter of not less than 9 mm. For producing this high strength steel rod, a high carbon steel after hot rolling is subjected to the so-called controlled cooling process, in which the rod rolled subjected to a phase transformation by the use of air cooling-medium under a controlled cooling condition. Thus, the rod obtained presents a structure consisting essentially of fine pearlite and has a tensile strength of above 115 kg/mm2. The steel rods of the present invention possess high tensile strength and are easily drawable into steel wire without the necessity for reheat treatment.