Welding die for welding powder

The invention provides a welding die for welding powder. The welding die comprises a die body and a die cover, the die cover detachably covers the die body, the die body is internally provided with a reaction cavity and a welding cavity, the reaction cavity is located above the welding cavity, the bottom of the reaction cavity is communicated with the welding cavity through a drainage trough, and the bottom face of the reaction cavity is provided with a metal spacer for preventing the welding powder in the reaction cavity from falling into the welding cavity before welding. The welding die is characterized in that the inner wall of the reaction cavity is provided with an annular step-level trough capable of retaining welding slag obtained after a reaction in the reaction cavity on the inner wall of the reaction cavity, and the diameter of the annular step-level trough is sequentially increased from bottom to top. The reaction cavity is composed of an upper reaction cavity body and a lower reaction cavity body, the top of the lower reaction cavity body is communicated with the upper reaction cavity body, the bottom of the lower reaction cavity body is communicated with the drainage trough, the annular step-level trough is located on the inner wall of the upper reaction cavity body, and the metal spacer is placed at the communicating position of the upper reaction cavity body and the lower reaction cavity body. The welding die has the advantages that the welding slag can be effectively prevented from entering a welding piece along with the molten welding powder, and welding quality is good.