Alloy steel powder for powder metallurgy, and sintered body

An Fe—Mo—Cu—C-based alloy steel powder for powder metallurgy, comprising:

• a partial diffusion alloy steel powder obtained by diffusionally adhering Mo to an iron-based powder;
• a Cu powder;
• and
• a graphite powder,
• wherein the partial diffusion alloy steel powder has a chemical composition consisting of Mo, Fe, and incidental impurities,
• the alloy steel powder for powder metallurgy has a chemical composition containing Mo:
• 0.2 mass % to 1.5 mass %, Cu:
• 0.5 mass % to 4.0 mass %, and C:
• 0.1 mass % to 1.0 mass %, with a balance being Fe and incidental impurities, and
• the iron-based powder has a mean particle size of 30 μm to 120 μm, and
• the Cu powder is a mixed powder of a Cu powder having a mean particle size of 25 μm or less and a Cu powder having a flat shape and satisfying a relation L≤−2d+50 where d is a thickness of the Cu powder in μm and L is diameter in a major axis of the Cu powder in μm.