RAIL Russian patent published in 2018 - IPC C22C38/04 E01B5/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to high-strength rail used on freight railways. Said rail is made of steel of the following composition, wt. %: C: from 0.75 to 1.20, Si: from 0.10 to 2.00, Mn: from 0.10 to 2.00, Cr: from 0 to 2.00, Mo: from 0 to 0.50, Co: from 0 to 1.00, B: from 0 to 0.0050, Cu: from 0 to 1.00, Ni: from 0 to 1.00, V: from 0 to 0.50, Nb: from 0 to 0.050, Ti: from 0 to 0.0500, Mg: from 0 to 0.0200, Ca: from 0 to 0.0200, REM: from 0 to 0.0500, Zr: from 0 to 0.0200, N: from 0 to 0.0200, Al: from 0 to 1.00, P: 0.0250 or less, S: 0.0250 or less, Fe and impurities – the rest. Metallographic structure between the outer surface of the lower part of the rail base and the depth of 5 mm is a pearlite structure for 90 % or more. Surface hardness of the lower center portion of the rail base (HC) located between the position ±0.05W from the center of the base width is HV 360–500. Surface hardness of the edge portion of the rail base (HE) located at both ends of the base with a length of 0.1W from the end portion of the base toward the center of the width of the base is HV 260–315, and the surface hardness of the middle part of the rail base (HM) located between HC and HE satisfies the following expression: HC≥HM≥HE, where W is the width of the bottom of the rail base.

EFFECT: rail has high breaking resistance and improved fatigue resistance.

3 cl, 10 dwg, 9 tbl