Quenching and Tempering Technology of Q960 Steel Used for Engineering Machinery

To develop Q960 steel plates used for engineering machinery, heat treatment technologyies of quenching and tempering was studies. The results show that the optimum quenching technology was heating at 900 ℃ for 20 min, and the optimum tempering technology was heating at 600 ℃ for 40 min. The microstructure of tested steel was temper sorbit after optimum quenching and tempering heat treatment, and yield strength, tensile strength, elongation and impact energy at -40 ℃ respectively was 1 030 MPa, 16.8% and 144 J, they could meet the acquirement of GB/T 16270-2009.