The invention discloses an
alloy cast steel for a
high speed train brake disc, a heat treatment method thereof and a
high speed train brake disc manufactured by the
alloy cast steel. The
alloy cast steel is composed of the following components in percentage by weight: 0.18-0.26% of carbon, 0.16-0.50% of
silicon, 0.55-1.40% of
manganese, not larger than 0.03% of
phosphorus, not larger than 0.03% of
sulfur, 0.90-2.00% of
chromium, 0.71-1.80% of
nickel, 0.65-1.20% of
molybdenum, 0.20-0.35% of
vanadium, not larger than 0.30% of other components, smaller than 0.1% of
tungsten and the balance of ferrum; and the heat treatment method comprises two steps of normalizing and
tempering. The alloy cast steel disclosed by the invention has the beneficial effects that such alloy elements as
manganese,
nickel,
chromium,
molybdenum,
vanadium, and the like, and such main components in the cast steel material as carbon,
silicon and the like are reasonably mixed and are effectively thermally treated to refine the crystalline grain and improve the
hardenability and
heat resistant properties of the alloy cast steel material, and the normal temperature strength and the high temperature strength are greatly improved, so that the alloy cast steel material has excellent comprehensive mechanical properties. A
brake disc manufactured by the alloy cast steel can meet the application requirements of high speed trains.