Partially diffusion bonded alloy has been used for components which require high mechanical properties. Secondary operations as a carburizing are used for these materials to achieve higher strength. Pre-alloyed 3Cr-0.5Mo steel powder can have excellent mechanical properties when it is sintered at 1250°C, followed by secondary operations: carburising or shot peening. This time the fatigue strength of 520MPa has been achieved after the same shot peening process by adjusting cooling rate of Carbon/Carbon Composite Mesh Belt Furnace for 3Cr-0.5Mo steel powder. The influence of sintering conditions on chemical analysis and the effect of controlling cooling rate on fatigue strength are discussed. Pre-alloyed 1.5Cr-0.5Mo steel powder are also discussed. Finally the paper describes the simulation methods of residual stress after shot peening.