| 摘要 |
1,256,013. Heat-treatment of rails. UNION CARBIDE CORP. Aug. 12, 1969 [Aug. 13, 1968], No. 40257/69. Heading C7N. Apparatus for treating railway rails includes a vertically adjustable lower roller 3, a pair of vertically adjustable rollers 2 and 4 substantially equidistant therefrom, at least one of said rollers being a driven roll, an additional pair of rollers 1 and 5 equidistant from 2 and 4 upstream and downstream respectively, all the rollers co-acting with a rail R as shown, and disposed between rollers 2 and 4, rail-head heating means 10, 11, 12, comprising a heating unit adapted to deliver heat at high intensity disposed upstream of one or more lower-intensity heating units and a railhead quenching means comprising a steam quench unit 13, 14, 15, downstream of the heating means and a water-quench unit 16 downstream of said steam-quench unit. Heating means 10, 11,12, are oxygen-fuel gas burners of decreasing heatoutput. The rail R is passed through the apparatus and is subjected to a bending moment by rollers 2, 3, and 4 which causes it to be curved in a direction opposite to that in which it would curve on quenching, the rail head being heated in the heating zone to a surface temperature of about 1,150‹C, and thereafter heated only sufficiently to maintain said temperature, being allowed to drop to 720-980‹C. before entering the quenching zone, being quenched therein to 454-593‹C. and maintained thereat, and being finally quenched to room temperature. A “ inch case of Brimell hardness 300-400 may be provided on a rail by the method. |
