Commonly used materials for CNC press brakemolds

       CNC press brake molds are widely used in the sheet metal processing industry, and are commonly used tools for sheet metal processing by bending machines.

       Bending molds can be divided into two categories, one is the upper mold (punch mold) and its accessories, and the other is the lower mold (concave mold) and its accessories. The mold assembly includes mold fixtures, molds, mold handles, mold heads, etc. The lower modules include lower molds, lower mold holders, mold bases, mold clamps, etc. They can be combined with each other. This needs to be done with mold materials.

       In use, the bending die will squeeze the plate surface through the upper die (punch die), and the lower die (concave die) will restrict the plate surface and deform the plate surface to form the desired shape. In this process, the board is bent and deformed, the material with the inner curved and rounded corners is compressed, and the outer board is stretched. During the entire production process, the mold material and the plate are inevitably squeezed and rubbed against each other. Therefore, the mold material will cause irreversible wear after long-term use. The contact surface between the mold material of the bending machine and the workpiece is usually a new surface; the contact pressure is extremely high, sometimes exceeding the yield strength of the processed material; the temperature of the contact surface is extremely high, which can reach 200-500℃, and the highest can reach 800-1000 ℃; The wear of mold materials is usually the result of mechanical wear, thermal deformation and chemical morphology.

       It is for this reason that WEIKEDA Machinery believes that several factors must be considered when selecting the mold material for the pipe bender: hardness, heat resistance and wear resistance. We generally choose T8-T12 carbon steel. Among them, T10 uses a large amount of steel, moderate toughness, and good wear resistance. The hardness can reach more than 60HRC after heat treatment. The production cost is low, but the hardenability is poor, and the heat resistance is poor (250 ℃). There are many molds in common bending machines. For better mold materials, 42CrMo high-strength alloy structural steel can be used. 42CrMo is an ultra-high-strength steel with high strength, strong toughness, good quenching performance, high fatigue limit after quenching and tempering, and resistance to multiple impacts. Work below ℃. At 45-48HRC, the hardness after heat treatment is better. At present, most of the molds of CNC bending machines use 42CrMo material. The better is the cold work die steel Cr12MoV, which adds a proper amount of chromium, molybdenum, vanadium and other alloying elements to the material to improve the hardenability and hardenability of the steel, so that the comprehensive mechanical properties of the quenched material far exceed other types Steel, suitable for various cold stamping dies with large cross-sections, complex shapes and frequently used. The mold made by this method has high precision and long life, but the material usage cost is relatively high.

       With the advent of the 21st century, new materials and new processes continue to emerge, and some will be added to the bending mold materials, let us wait and see.