Influence of conditions of heat treatment on the mechanical properties of steel 5160H

In this work, the influence of quenching and tempering heat treatments conditions on the mechanical properties of hardness, toughness and mechanical strength of steel 5160H was investigated. To achieve this aim, chemical composition, the austenitizing temperature, hold time and tempering temperature were varied. The evaluation of mechanical properties was made by hardness Rockwell C, Knoop microhardness and mechanical strength using a universal machine and the toughness by Charpy impact test. The chemical composition was studied using optical emission spectroscopy (OES), the microstructure by scanning electron microscopy (SEM) and the precipitates by transmission electron microscopy (TEM). The best mechanical properties were achieved in alloy having low microalloying element combined with the higher austenitizing temperature of 1000 degrees C and greater hold time of 30 minutes during the quenching process. This information will be useful to the automotive industry due to use of this material in the manufacture of springs.