Abstract
Surface finish rolling experiments were carried out using rollers and helical gears of 1.5Cr-0.2Mo alloyed sintered steel having the density of 7.00〜7.60 g/cm^3. A two roller dies transverse CNC form rolling machine was employed. Two kinds of FEM model of 2-dimensional and 3-dimensional were proposed to simulate the surface densification process of rollers. Pore structures in the densified surface layer were examined and the effects of initial density of P/M material on densification properties were compared and evaluated. The experimental results show that the surface densification of P/M material with the initial density of 7.25 g/cm^3 or more has possibilities to make the part surface to a depth fully dense by optimizing the rolling condition. The simulation results in 3-dimensional model agree well with the experimental ones in the surface densification behaviors.
