Patent ID: 8092916

Claim:
A steel wire rod comprising C: 0.05-1.2 mass %, Si: 0.01-0.50 mass %, Mn: 0.1-1.5 mass %, P: 0.02 mass % or below (inclusive of 0%), S: 0.02 mass % or below (inclusive of 0%), N: 0.005 mass % or below (inclusive of 0%), and the balance of iron and inevitable impurities in which the steel wire rod has an Fe 2 Sia 4 layer formed on its surface, an inner layer scale formed on an outer surface of the Fe 2 SiO 4 layer, and an outer layer scale formed on an outer surface of the inner layer scale, the inner layer scale comprises an FeO layer comprising fine crystal grains having random orientation, formed at the outer surface of the Fe 2 SiO 4 layer, the outer layer scale comprises an FeO layer formed at the outer surface of the FeO layer of the inner layer scale, an Fe 3 O 4 layer formed on the outer surface thereof and an Fe 2 O 3 layer formed on the outer surface of the Fe 3 O 4 layer, the inner layer scale having a thickness that is 1-40% of the thickness of the entire scale, which is the thickness of the inner layer scale+the outer layer scale, the Fe 2 SiO 4 layer having a thickness of from 0.01-1.0 μm, a ratio of {100} orientation occupying the entire FeO crystal grains of the inner layer scale is 10% or less, and a ratio of {100} orientation occupying the entire FeO crystal grains of the outer layer scale is 20% or more.