Comparing properties of the 42SICR steel after conventional heat treatment and QP processing

To improve the mechanical properties of high strength steels the application of innovative methods is often necessary. One of such technology used in the field of heat treatment (HT) is the quenching and partitioning process. By this method higher content of stabile retained austenite (RA) can be achieved, which increase material ductility while its strength remains only slightly reduced. The experiment compares the mechanical properties of the 42SiCr steel heat treated conventionally or by the QP process. Parameters were designed for both HT modes to achieve approximately the same tensile strength and then the elongations and RA contents were compared. As part of the experiment the metallographic analysis, the X-ray diffraction analysis, hardness measurement and tensile test were performed. The results showed improvement of mechanical properties of the samples treated by QP process. The conventionally treated material (with RA content of 8 %) showed the elongation of 10% at the tensile strength of 1980 MPa while the specimen processed by QP reached elongation of 14% at a tensile strength of 2000 MPa and RA content was also higher (11%). On the basis of this knowledge the future research will be focused on the optimization of QP process parameters