Solving the problem of strain in the mold and workpiece forming process should be based on the basic principle of reducing adhesive wear, and changing the nature of the contact pair as a starting point. Hereinafter, the three sides of the pair of contact pairs are formed, that is, the raw materials of the formed workpiece, the workpiece and the mold, and the mold are separately analyzed.
The contact properties of the stretched material with the convex and concave molds are changed by changing the convex or concave mold material of the mold or by surface-treating the convex or concave mold or by selecting a suitable mold material. Practice has proved that this is an economical and effective method to solve the problem of strain, and it is also a widely used method.
The standard heat treatment process is also a problem at present. For the structure of the drawing die and the mechanical properties of the die steel, heat treatment is required, especially for large and complex tensile members, and the size of the heat-treated workpiece is placed in the furnace. The process of uniform and reasonable heating has high requirements, dimensional deformation and cracking often occur, and the higher hardness increases the difficulty and cycle length for the subsequent processing, thereby increasing the cost.