Optimization of corrosion resistance and mechanical properties on quenched and tempered rebar

Quenching and tempering of rebar is a process whereby a surface layer of tempered martensite is created on a ferritic-pearlitic core. The tempering temperature determines the tensile properties, but quenching reduces the corrosion resistance. To optimize the corrosion resistance and find suitable steel compositions, experiments were carried out, using a two-level experimental method for relevant control parameters, combined with cooling to different tempering temperatures from 940 to 560degreesC. Low tempering temperatures improve the corrosion resistance. The tensile properties can be described by equations derived from the experiments.