Why does the drawing die strain and the solution

       To solve the problem of strain in the process of drawing dies and workpieces, we should follow the basic principle of reducing adhesion and wear, and change the nature of the contact pair as the starting point.

1. The raw material aspect of the formed workpiece

By surface treatment of the raw materials, such as phosphating, spraying or other surface treatments on the raw materials, a non-metallic mold layer is formed on the surface of the formed material, which can greatly reduce or eliminate the strain on the workpiece. This method is often more costly. High, and need to add additional production equipment and increase the production process, although this method sometimes has some effect, in actual production applications are very few.

2. Between the workpiece and the mold

Adding a layer of PVC or other film between the mold and the forming material can sometimes solve the problem of strain on the workpiece. For the production line, the film can be continuously supplied through the mechanism, and for the cyclical stamping equipment, a film needs to be added for each workpiece produced, which affects the production efficiency. This method is generally costly and also produces a large amount of waste. For small batches It is advisable to use this method for the production of large-scale workpieces.

In some occasions where the forming load is small, sometimes the problem of strain on the workpiece can be solved by adding lubricating oil or adding EP additive lubricating oil.

3. Mould

By changing the convex and concave ink materials of the mold or performing surface treatment on the convex and concave molds of the mold, the contact properties of the material to be formed and the convex and concave molds are changed. Practice has proved that this is an economical and effective method to solve the strain problem, and it is also a widely used method at present.

In summary, there are many ways to solve the problem of surface strain on the workpiece and mold convex and concave molds. For specific cases, the application method should be selected according to the size of the workpiece and the load, the production batch, and the type of material to be processed. Among all the methods to solve the problem of strain, it is best to use cemented carbide as the mold material and chemical vapor deposition and TD coating treatment on the convex and concave surfaces of the mold. Among them, TD cladding is the most cost-effective