Low-expansion high-temperature alloy steel ingot, preparation method and application

The invention discloses a low-expansion high-temperature alloy steel ingot, a preparation method and application, relates to the technical field of high-temperature alloy smelting, and determines the precipitation temperature range of Laves, epsilon and gamma phases in the solidification and cooling process of the low-expansion high-temperature alloy steel ingot through thermodynamic analysis of the solidification process of the low-expansion high-temperature alloy steel ingot. Red feeding annealing at the temperature of 940-990 DEG C is adopted, so that thermal stress in the steel ingot can be eliminated, precipitation of a strengthening phase is prevented, the influence of structural stress on an electrode bar is avoided, and cracks are prevented from being generated in the electrode bar. After the technical scheme is adopted, in the vacuum self-consuming smelting process of the electrode bar, the melting speed is stable, the molten pool is stable, the block falling phenomenon in the self-consuming process