Iron base sintered alloy having highly densified and hardened surface, and producing method thereof

摘要

An iron base sintered alloy having highly densified and hardened surface and a producing method thereof are provided. The iron base sintered alloy includes an iron base sintered alloy surface layer portion having a thickness in a range of 1 mum to 2 mm from a surface of the iron base sintered alloy and containing K and/or Na in an average concentration of 0.0001 to 1 mass %, or having an average concentration of P higher than a concentration of P in an iron base sintered alloy inner portion located inside the iron base sintered alloy surface layer portion and containing K and/or Na in an average concentration of 0.0001 to 1 mass %.