The Effect of Quenching and Partitioning Process on the Microstructure and Tensile Properties of a Medium Carbon High Silicon Steel*

One of the practical methods for developing high strength steels with suitable ductility is quenching and partitioning process to create a micro-composite microstructure (martensite + residual austenite). In this regard, a good combination of mechanical properties can be produced in a low-alloy steel with a low cost. In the present study, a medium silicon carbon steel 1.7102 was studied by applying quenching and partitioning processes. For this purpose, the effect of quenching temperature (temperature range 170 to 230 °C) and partitioning time (3 to 30 min) were investigated on the microstructure and tensile properties. Microstructural observation was carried out by light microscopy and the volume fraction of the retained austenite was determined using the X-ray diffraction technique. The results show that quenched and partitioned microstructure contains micro-composite features. Moreover, the amount of retained austenite was reduced by increasing the partitioning time followed by precipitation of carbide phase. The best tensile properties were obtained for the specimen quenched at 170 ° C and partitioned at 300 ° C for 8 minutes with a tensile strength of 1997 MPa, yield strength of 1730 MPa, elongation of 10.3% and reduction area of 48%.