METHOD FOR MANUFACTURING A CARBURIZED PART AND STEEL PART

[Task] To provide a manufacturing method of a carburized part, which is capable of producing a large amount of fine carbides on a surface by a case hardening process, and thus, capable of producing carburized parts having high surface hardness and high strength. [Means of Solving the Problem] A steel has a composition containing, by mass percent, C: 0.15 to 0.25%, Si: 0.90 to 1.30%, Mn: 0.70 to 1.10%, P: 0.030% or less, S: 0.100% or less, Cu: 0.01 to 0.50%, Ni: 0.01 to 0.50%, Cr: 0.20 to 0.50%, Mo: 0.50% or less, Al: 0.30% or less, N: 0.05% or less, and a balance of Fe and unavoidable impurities, and satisfying the following Expression (1) Si + Ni + Cu - Cr > 0.5 This steel is vacuum carburized so that a surface carbon concentration falls in a range of 0.9 to 1.5%, and then, is air-cooled to transform a surface structure into pearlite, and thereafter, cementite is divided by induction hardening, thereby producing fine carbides containing 90% or more of carbides of 1 µm or more.