Patent ID: 7967921

Claim:
A carburized component having a base metal comprised of a steel containing: C: 0.10% by mass to 0.40% by mass; Si: 0.05% by mass to 0.8% by mass; Mn: 0.35% by mass to 1.2% by mass; Cr: 2.0% by mass to 4.64% by mass; both ends inclusive, and remnant including Fe and inevitable impurities, having a carburized layer formed on a surface layer portion of said base metal, having a grain boundary oxidized layer depth of 1 μm or less on a surface thereof and an average C concentration SC of 1.5% by mass to 4.0% by mass, both ends inclusive, at 25 μm deep from the surface, and adjusted so as to satisfy: 1.76 SC− 1.06 <WCr< 1.76 SC+ 0.94 (1) where WCr represents a Cr content of the steel composing said base metal, wherein said carburized layer also has, in a sectional structure in depth direction thereof, a carbide area ratio of 15% to 60%, both ends inclusive, at 25 μm deep from the surface, a fine carbide area ratio, having a dimension of 0.5 μm to 10 μm, both ends inclusive, constitutes 80% or more of the total carbide area, and further M 3 C type carbide accounts for 70% by volume or more of said fine carbide, wherein M is a metal.