The influence of different heat treatment strategies on the microstructure and properties of 42SiCr steel was investigated.To compare the benefit of innovative treatment methods with more conventional ones,several strategies based on a new quenching and partitioning (Q-P) process were designed together with several strategies using more traditional quenching and tempering process.Different combinations of mechanical properties were obtained with ultimate strengths in the range of 1818-2120 MPa and ductility between 10% and 24%.Resulting microstructures were martensitic with 0-12% of retained austenite and they were analyzed by laser scanning confocal microscopy,transmission electron microscopy and X-ray diffraction phase analysis. The influence of different heat treatment strategies on the microstructure and properties of 42SiCr steel was investigated. To compare the benefit of innovative treatment methods with more conventional ones, several strategies based on a new quenching and partitioning (QP) process were designed together with several strategies using more traditional quenching and tempering processes. Different combinations of mechanical properties were obtained with ultimate strengths in the range of 1818-2120 MPa and ductility between 10% and 24%. Resulting microstructures were martensitic with 0-12% of retained austenite and they were analyzed by laser scanning confocal microscopy, transmission electron microscopy and X-ray diffraction phase analysis.