Heat treatment technique of large-size GCr15 steel

The invention relates to the field of metal working, and discloses a heat treatment technique of large-size GCr15 steel, which comprises the following steps: a) heating large-size GCr15 steel with the diameter of 20-150mm to 835-850 DEG C, and keeping the temperature for 30-60 minutes; b) carrying out water quenching at the water temperature of 20-60 DEG C; c) when the color on the product surface darkens and red completely disappears, immediately taking the product out of water and carrying out oil quenching; and d) after quenching, tempering the product. The heat treatment technique adopts a double quenching method; in the GCr15 steel heat treatment quenching process, the material is firstly subjected to pre-quenching with the water medium with favorable thermal conductivity, and then subjected oil quenching after the surface layer is hardened, thereby completing the final quenching technique; and finally, the material is tempered. The technique can enable the surface layer of the large-size GCr15 steel to reach high hardness, and enhances the abrasion resistance of the material as compared with the existing technique.