This invention discloses a heat treatment method for
train wheels, comprising the steps of: S1, heating the wheel; S2, water-
quenching the wheel; and S3,
tempering the wheel. In step S2, a composite
nozzle is used, with a first
nozzle region, a second
nozzle region, and a third nozzle region sequentially arranged on the composite nozzle. The first nozzle region is equipped with a first nozzle for spraying air onto the wheel
tread surface, the second nozzle region is equipped with a second nozzle for spraying water mist onto the wheel
tread surface, and the third nozzle region is equipped with a third nozzle for spraying cooling water onto the wheel
tread surface. This heat treatment method for
train wheels utilizes a composite nozzle during
quenching to reduce the near-
surface cooling rate of the wheel tread surface. By employing
compressed air and appropriately adjusting the flow rate of cooling water (small / large flow), the rapid cooling of the near-
surface layer of the rim is reduced, effectively increasing the
cooling rate of the internal matrix. This results in a more uniform
microstructure in the radial direction of the wheel rim, achieving a uniform transformation of the internal
microstructure and reducing the
hardness gradient.