Method For Railway Rolling Stock Unit Center Plate Strengthening And A Device to Perform It

Abstract

The invention relates to the field of metallurgy, in particular to the methods for heat treatment of railway rolling stock parts, specifically railway rolling stock unit center plate. The center plate strengthening device contains a power coil and a sprayer, the power coil being implemented as turnable against the center plate central axis and containing a tube with spray cooling openings. The method for railway rolling stock unit center plate strengthening is performed by progressive induction hardening with simultaneous liquid cooling while rotating the center plate strengthening device 360° around the central axis where the center plate treated surfaces undergo induction heating, spray cooling immediately after the heating, and low-temperature volume tempering with a dwelling period.

1 . A method for railway rolling stock unit center plate strengthening, which includes the center plate fastening against the center plate strengthening device, induction heating of the center plate surfaces being strengthened with subsequent cooling by a coolant carried out by the center plate strengthening device, characterized in that it is performed by progressive induction hardening with simultaneous liquid cooling while rotating the center plate strengthening device 360° around the central axis, where the center plate treated surfaces undergo induction heating to temperature T within the range of 830-1150° C. and, immediately after the heating, are cooled by spray with coolant flow of 15 to 45 l/min, thereafter low-temperature volume tempering is performed at 180-250° C. with 1 to 5 hr dwelling period. 
     
     
         2 . The method according to  claim 1 , characterized in that full rotation of the center plate strengthening device is performed within 2-10 minutes. 
     
     
         3 . The method according to  claim 1 , characterized in that the center plate strengthening device is located at a distance L from the center plate surface being hardened, within the range of 0.5 to 7 mm. 
     
     
         4 . The method according to  claim 1 , characterized in that the hardening is performed to a depth of up to 5 mm. 
     
     
         5 . A center plate strengthening device containing a power coil and a sprayer, characterized in that the power coil is implemented as turnable against the center plate central axis and containing a tube with spray cooling openings. 
     
     
         6 . The center plate strengthening device according to  claim 5 , characterized in that the power coil is implemented as L-shaped. 
     
     
         7 . The center plate strengthening device according to  claim 5 , characterized in that the power coil contains an additional tube with spray cooling openings. 
     
     
         8 . The center plate strengthening device according to  claim 5 , characterized in that the power coil is fastened with a clamp coaxially with the center plate central axis.