The influences of chromium addition and quenching treatment on the mechanical properties and fracture behaviors of diffusion-alloyed powder metal steels

The results showed that the addition of Cr helps strengthen and homogenize the sintered microstructure. The tensile strength is thus improved by 38%, while the impact energy is lowered by 15%. Quenching treatment improves the tensile strength by 46% because martensite forms at the expense of low-strength pearlite. However, the loss of impact energy due to quenching treatment is as high as 32%. These findings demonstrate that the addition of Cr is a feasible method to strengthen diffusion-alloyed PM steels without obviously sacrificing toughness.