Through different heat treatment processes:800、820 ℃ low temperature quenching + 600℃ tempering、 880 °C +860 °C twice quenching + 600℃ tempering and 860 °C once quenching + 600 °C tempering
the heat treatment experiment on 40CrMnMo steel has been carried out to study the effects of three kinds of heat treatment processes on the microstructure and properties of the 40CrMnMo steel. The results show that the tensile strength of tested steel by the three kinds of heat treatment processes is similar (936 ~951 MPa)
and the microstructures is tempered martensite + ferrite
the impact energy of tested steel of (800、820 °C ) low temperature quenching and 600 °C tempering heat treatment processes is highest (65 ~69 J).