Nanostructure atomic image and mechanical properties of a novel wear resistance steel with high strength and toughness

The microstructures of medium carbon wear resistance steel after quenching and tempering are martensite and small amount of bainite, retained austenite and carbide. The impact toughness with U notch as cast afrer air cooled was within 38～50?J/cm 2, and the impact toughness without notch was 140～290?J/cm 2. with hardness HRC =53～56; while in forged stage, their hardness was HRC =52～54, the impact toughness with U notch was 50～70?J/cm 2, and the tensile strength σ b =1850～2000?Mpa. The impact toughness of the studied medium carbon low alloy steel containing martensite, bainite and small amount of retained austenite is 40% higher than that of normal Mn B and Mn Si B bainitic steels. The nanostructure atomic image of the steel was observed with high resolution electron microscopy and the sizes of subplate of bainitic ferrite were determined.