How to prevent the deformation of stamping die during processing.

In the process of stamping die processing, corresponding measures should be taken to prevent die deformation, including design optimization, material selection and treatment, processing technology control and subsequent heat treatment and surface treatment. The following are specific methods:

Optimize mold design

Reasonable design of die structure: in the design stage, fully consider the stress of the die to avoid stress concentration areas. For example, adopt reasonable transition fillet and avoid sharp internal corner to reduce stress concentration. For large or complex molds, stiffeners or supporting structures can be designed to improve the rigidity of the mold.

Considering the processing technology: the design should be convenient for processing and clamping, so as to avoid difficult parts or unstable clamping. For example, the structures such as deep holes and narrow grooves should be reduced as much as possible, and the processing sequence and method should be planned reasonably for the unavoidable ones.

Select the appropriate mold material

Material selection according to the requirements of die use: according to the material, thickness, production batch and stamping process of stamping parts, the appropriate die material is selected. Generally speaking, materials with good toughness should be selected for dies bearing large impact load; For molds requiring high hardness and wear resistance, alloy steel containing alloying elements such as chromium, molybdenum and vanadium can be selected.

Ensure the quality of materials: ensure the quality of the selected mold materials is reliable, and there are no internal defects, such as porosity and porosity. When purchasing materials, you should ask the supplier for the quality certificate of the materials, and carry out necessary inspection and testing, such as metallographic analysis and hardness testing.

Control processing technology

Reasonable arrangement of machining sequence: follow the principle of rough machining first and then finishing, and remove most of the allowance during rough machining to make the mold close to the final shape, but leave some machining allowance for finishing. After rough machining, arrange proper aging treatment or tempering treatment to eliminate machining stress, and then finish machining, which can reduce the deformation caused by stress release.

Adopt appropriate cutting parameters: select appropriate cutting speed, feed and cutting depth to avoid excessive cutting force. For example, in milling, using smaller cutting depth and higher feed speed is beneficial to reduce cutting force and cutting heat, thus reducing the possibility of die deformation. At the same time, according to the characteristics of mold materials and tools, cutting fluid should be selected reasonably to play the role of cooling and lubrication and reduce the generation of cutting heat.

Optimize the clamping method: choose the appropriate clamping method and position to ensure the clamping is firm and evenly stressed. Avoid mold deformation during machining due to improper clamping. For example, for thin-plate mold parts, vacuum sucker or magnetic fixture can be used for clamping to ensure the stability and uniformity of clamping.

Carry out proper heat treatment

Correct formulation of heat treatment process: according to the mold material and use requirements, formulate reasonable heat treatment process, including quenching, tempering, tempering and so on. In the quenching process, the heating speed, holding time and cooling speed should be well controlled to avoid mold deformation caused by too fast heating or uneven cooling. For example, for high alloy steel dies, methods such as step quenching or isothermal quenching can be adopted to reduce quenching stress.

Straightening after heat treatment: For the mould parts with slight deformation after heat treatment, the straightening process can be used to correct them. However, attention should be paid to the method and strength in the straightening process to avoid new stress or damage to the mold.

Implement effective surface treatment.

Select the appropriate surface treatment method: according to the requirements of the mold, select the appropriate surface treatment process, such as nitriding, hard chromium plating, electroless nickel plating, etc. These surface treatment methods can improve the hardness, wear resistance and corrosion resistance of the die, and also help to reduce the deformation of the die during use. For example, nitriding treatment can form a nitride layer with high hardness and good wear resistance on the surface of the die, and improve the surface hardness and anti-seizure performance of the die.

Control the process parameters of surface treatment: During surface treatment, strictly control the process parameters, such as treatment temperature, time and gas flow rate, to ensure the quality and uniformity of the surface treatment layer. The uneven surface treatment layer may cause the mold to deform due to uneven stress during use.