Effect of Tempering Temperature on the Mechanical Properties and Microstructure of low alloy Steel DIN 41Cr4

摘要

This research is focused on the effect of tempering temperature on the microstructure and mechanical properties of low alloy steel DIN 41Cr4 used for the manufacture of bolts, threaded, screws and shafts by manufacturing company in Algeria. We use an experimental approach by applying heat treatment of quenching and tempering temperature. Mechanical testing of tensile, impact fracture toughness, hardness tests and microstructures were conducted on all the heat-treated samples. All samples were austenitized at 850°C for 30 min followed by oil quenching, and then tempered at temperatures between 200 and 600 °C for 1h and air cooledin order to investigate the influence of microstructure. The results of tensile testing indicated that yield strength (YS), ultimate tensile strength (UTS) and the hardness decrease with increasing tempered temperature, but the elongation, impact energy and grain size increase with increasing the tempering temperature.