Abstract: In an H-section steel, which has a predetermined chemical composition, a thickness of the flange is from 25 to 140 mm; an average crystal grain diameter is 38 ?m or less and the area fraction of a martensite-austenite constituent is 1.2% or less, in a plane orthogonal to the width direction of the flange, centering on a measurement position 7 that is a position separated, in the width direction of the flange, from the end face in the width direction of the flange by (?)F, and separated, in the thickness direction of the flange, from the outer face in the thickness direction of the flange by (¼)t2, when the width direction length of the flange is F and the thickness of the flange is t2; a yield strength or 0.

Abstract: In an H-section steel, which has a predetermined chemical composition, a thickness of the flange is from 25 to 140 mm; an average crystal grain diameter is 38 ?m or less and the area fraction of a martensite-austenite constituent is 1.2% or less, in a plane orthogonal to the width direction of the flange, centering on a measurement position 7 that is a position separated, in the width direction of the flange, from the end face in the width direction of the flange by (?)F, and separated, in the thickness direction of the flange, from the outer face in the thickness direction of the flange by (¼)t2, when the width direction length of the flange is F and the thickness of the flange is t2; a yield strength or 0.

Abstract: Abrasion resistant steel having a chemical composition comprising, by mass %, C: 0.10 to 0.20%, Si: 0.01 to 1.20%, Mn: 0.01 to 2.00%, P: less than 0.017%, S: 0.010% or less, Cu: 0.01 to 0.70%, Ni: 0.01 to 1.00%, Cr: 0 to 1.50%, Mo: 0 to 0.80%, W: 0 to 0.50%, Nb: 0 to 0.050%, V: 0 to 0.20%, Ti: 0 to 0.030%, B: 0 to 0.0030%, N: 0.0001 to 0.0070%, Al: 0.001 to 0.10%, Ca: 0 to 0.0050%, Zr: 0 to 0.0050%, Mg: 0 to 0.0050%, REM: 0 to 0.0050%, and a balance of Fe and impurities, having metal structures at a position of ¼ of the thickness from the surface in a thickness direction, which have a total of the area ratios of martensite and lower bainite of 50 to 100% and a prior austenite average grain size of 5 to 23 ?m, and having a Brinell hardness at a position of 1 mm from the surface in the thickness direction of 360 to 440, and a method for producing the same.