HEAVY-LOAD SOLID DISK WHEEL AND WHEEL TYRE FOR SELF-PROPELLED TRAINS AND CARS AND METHOD OF THERMAL TREATMENT OF WHEELS AND TYRES Russian patent published in 1997 - IPC

FIELD: railway transport; disk wheels and tyres for self-propelled trains and cars made of malleable, rolled, alloy steel of improved condition. SUBSTANCE: it has been revealed that one of causes of wheel and tyre breakage is insufficient viscosity of quality steels. For this purpose new steel has been created which has the following chemical composition: carbon, 0.38 - 0.42; silicon, not exceeding 0.25; manganese, 0.40-0.60; phosphorous, not exceeding 0.012; sulfur, not exceeding 0.005; chromium, 1.00-1.5; molybdenum, 0.30-0.60; nickel, 0.7-1.2; aluminium, 0.015-0.040; nitrogen, not exceeding, 0.008; and iron, the balance. Wheels and tyres are subjected to thermal treatment: hardening with tempering. They are heated to 850 C, cooled in water or oil at room temperature (about 20 C), then heated to 600 C, cooled in the air at room temperature (about 20 C). After such treatment wheels and tyres acquire higher viscosity potential with preservation of their strength properties. EFFECT: reduced damage to wheels at long braking. 3 cl