X40CrMoV5-1 steel, as a hot work die steel, is characterized by its excellent high-temperature performance combination, which combines high toughness and high-temperature strength, making it particularly suitable for repeated thermal cycling conditions such as die-casting molds; X40CrMoV5-1 steel undergoes electroslag remelting process to ensure material uniformity, and with optimized heat treatment process, it can achieve 48-52HRC hardness. X40CrMoV5-1 steel has excellent resistance to thermal fatigue, aluminum/copper alloy erosion, and extremely low heat treatment deformation rate. After surface nitriding treatment, the hardness can reach HV1000 or above, significantly extending the mold life.