Heat treatment method for engine valve

The invention discloses a heat treatment method for an engine valve. The methodcomprises the following steps: 1, an engine valve sample is put into a furnace, and the sample is heated to 1150-1200 DEG C; 2, timing and heat preservation are conducted, and the heat preservation time is 3-10 min; and 3, after the heat preservation time is ended, the furnace is opened immediately, the sample is taken out, and cooling is carried out. According to the method, the solid solution heat treatment process parameters are reset, the solid solution temperature is increased to 1150-1200 DEG C, the influence of the temperature rising process on the structure change is reduced by shortening the solid solution heat preservation time, the problems of crystal mixing and uneven crystal grains at all positions of the high-temperature alloy material valve are solved, the high-temperature strength and durability of the product are improved, the overall heat treatment time is shortened, and the cost and the production scheduling pres