RAIL Russian patent published in 2022 - IPC C21D9/04 C22C38/00 C22C38/58 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to a rail used on freight railways. The rail is made of steel, including, wt. %: C 0.75-1.20, Si 0.10-2.00, Mn 0.10-2.00, Cr 0-2,00, Mo 0-0,50, Co 0-1,00, B 0-0,0050, Cu 0-1,00, Ni 0-1,00, V 0-0,50, Nb 0-0,050, Ti 0-0,0500, Mg 0-0,0200, Ca 0-0,0200, REM 0-0,0500, Zr 0-0,0200, N 0-0,0200, Al 0-1,00, P 0.0250 or less, S 0.0250 or less and a residue of iron and impurities in which 90% of the area or more of the metallographic structure in the cross section of the rail neck part is a perlite structure. The minimum hardness value in the cross section of the rail neck part is 300 or more HV, the difference between the maximum and the minimum hardness values in the cross section of the rail neck part is 40 or less HV. The specified cross-section of the part of the rail neck represents an area in the range of +/-15 mm in the up-down direction of the rail from the midline between the upper part of the rail and the lower part of the rail, and the mentioned hardness was measured with a Vickers hardness tester with a load of 98 H, while the recesses were continuously performed in the direction of the thickness of the part of the rail neck in a row with a step of 1.0 mm, in this case, the starting point of continuous indentation is the position at a depth of 1.0 mm from the outer surface of the part of the rail neck, and the hardness measurement was performed on at least five lines.

EFFECT: suppression of fatigue damage arising from a part of the rail neck is provided, rail has a high resistance to fatigue failure.

3 cl, 5 dwg, 4 tbl