Heat treated steel product having high strength and excellent chemical conversion coating ability and method of production of same
View Patent ↗A steel product bent by heating to 600° C. or more, specifically a heat treated steel product having high strength and excellent chemical conversion coating ability which has scale with FeO content of 90% or more, having a thickness of 1 μm or less on the surface.
1. Heat A heat treated steel product comprising a scale with FeO content of 90% or more, having a thickness of 1 μm or less on a surface,
wherein a maximum value and a minimum value of a thickness of the scale are within ±10% of an average value of the thickness.
2. The heat treated steel product according to claim 1 , wherein the steel has a structure consisting of martensite, or martensite and tempered martensite.
3. The heat treated steel product according to claim 1 , wherein the steel product is a hollow member having a closed horizontal cross-sectional shape.
4. The heat treated steel product according to claim 2 , wherein the steel product is a hollow member having a closed horizontal cross-sectional shape.