METHOD OF MANUFACTURING A BRAKE HILL SHOE Russian patent published in 2021 - IPC B61H7/10 B61K7/16 B60T3/00 

FIELD: railroads.

SUBSTANCE: invention relates to a method for manufacturing a brake shoe, which includes making a runner from low-carbon hot-rolled steel containing carbon - 0.17-0.27%; silicon - 0.17-0.37%; manganese - 0.35-0.50%; phosphorus - no more than 0.040%; sulfur - no more than 0.050%; chromium - no more than 0.30%; nickel - no more than 0.30%; copper - no more than 0.30%; iron and inevitable impurities - the rest, and pads made of low-carbon cast steel containing 0.17-0.30% carbon; silicon 0.20-0.35%; manganese 0.40-0.50%; phosphorus - no more than 0.040%; sulfur - no more than 0.050%; chromium - no more than 0.30%; nickel - no more than 0.30%; copper - no more than 0.30%; iron and inevitable impurities - the rest, assembling them with rivets to obtain a brake shoe. Then the shoe assembly is heated to a temperature of 870 – 930 °C. Quenching cooling of the shoe assembly is carried out by the method of volumetric spraying, in which the movement of the coolant is provided at such a speed that, in the temperature range of the lowest stability of austenite 550 – 720 °C, the quenched surface of the parts is cooled at a rate sufficient to obtain the critical speed in its lower range at a given thickness of the part, with the provision of a troostomartensite structure in the surface layer and a troostosorbitic structure in the core. In this case, tempering is not applied. EFFECT: elimination of the process of seizure and welding of a skid with a rail head or a wheel with a shoe under extreme braking conditions.

3 cl, 5 tbl, 12 dwg