Patent ID: 8221899

Claim:
A steel material, comprising Fe and: C: 0.01 to 0.30 mass %; Si: 0.1 to 3.00 mass %; Mn: 0.1 to 3.00 mass %; P: 0 to 0.10 mass %; S: 0 to 0.05 mass %; and N: 0 to 300 ppm, wherein a ratio of an oxide present in a grain boundary and an oxide present in grains comprising Mn and Si at a total amount of 1 at % or more, as oxides present in a steel region at a depth from a steel body surface of the steel material to 20 μm, is 5% or more and less than 20% as an average area ratio occupied in the steel region, wherein a ratio occupied by an outer oxide comprising Mn and Si at a total amount of 1 at % or more, which is present on the steel material surface, is 0.1% or more and less than 50% as an average ratio of a total length of the oxide occupied for a length of 1 μm in a substantially horizontal direction of an interface between a steel body and an outer oxide layer.