METHOD OF HEAT TREATMENT OF RAILWAY WHEELS MADE OF STEEL Russian patent published in 2024 - IPC C21D9/34 C22C38/50 C22C38/48 C22C38/46 C22C38/44 C22C38/42 

FIELD: metallurgy.

SUBSTANCE: invention relates to thermal treatment of railway wheels. Proposed method comprises heating wheels to austenitizing temperature, quenching by cooling the wheel rim working layer, then holding the wheel in air and tempering. Wheel made of steel containing the following components (wt.%) is heated to austenitizing temperature: C 0.68–0.78, Mn 0.60–1.00, Si 0.22–0.65, Cr 0.20–0.60, Ni≤0.35, V 0.05–0.15, Mo≤0.08, S 0.005–0.015, P≤0.020, Cu≤0.25, Ti≤0.03, Nb≤0.01, Fe—the rest. Quenching by cooling the working layer of the wheel rim is carried out for 360 seconds. Cooling along the wheel rim rolling circle is carried out with water flow rate adjustment during the cooling period, respectively: from 0.0040 to 0.0060 l/(cm²·s) in period of 90 seconds, from 0.0060 to 0.0090 l/(cm²·s) in period of 30 seconds, from 0.0090 to 0.0120 l/(cm²·s) in period of 30 seconds, from 0.0120 to 0.0150 l/(cm²·s) in period of 30 seconds, from 0.0150 to 0.0165 l/(cm²·s) in period of 30 seconds, from 0.0165 to 0.0175 l/(cm²·s) in period of 30 seconds, from 0.0175 to 0.0190 l/(cm²·s) in period of 30 seconds and from 0.0190 l/(cm²·s) to 0.0300 l/(cm²·s) in period of 90 seconds. Inner side surface of the wheel rim is cooled with air at an air flow rate of 0.015–0.020 m³/(cm²·s) for period of 360 seconds.

EFFECT: invention enables to obtain wheels with high mechanical properties and high wear resistance.

1 cl, 4 tbl, 1 ex