IRON BASE SINTERED ALLOY EXHIBITING HIGH SURFACE DENSIFICATION AND HIGH SURFACE HARDNESS, AND METHOD FOR PRODUCTION THEREOF

摘要

An iron base sintered ally exhibiting high surface densification and high surface hardness, characterized in that it comprises a sintered alloy surface layer portion which has a thickness in the range of 1 mum to 2 mm from the surface thereof and contains K and/or Na in an average concentration of 0.0001 to 1 mass % or in that it comprises a sintered alloy surface layer portion which has an average P concentration being higher than that in the inner portion of the sintered alloy by 0.01 to 1 mass % and contains K and/or Na in an average concentration of 0.0001 to 1 mass %; and a method for the iron base sintered ally.