Concrete reinforcing rods - are quenched after hot rolling and profiling

摘要

Ribbed (grooved) surface concrete reinforcing steel rod for welded reinforcing steel rod for welded reinforcing grids are subjected after hot rolling and hot profiling to single step forced water jet cooling at the rate of min. 100 degrees C/sec. to obtain a surface zone temp. of 100-300 degrees C following which the material is coiled and ambient air cooled to yield to yield a high strength martensitic outer zone and a tough ferrite-pearlite structured core material. The outer skin hardness is pref. 1.4-1.7 times harder than the core. The material suffers no deterioration from welding and can be bent without risk of cracking or breakage.