How to guarantee the precision stamping parts’ quality

stamped stainless steel

Stamping can produce parts with reinforcement, ribs, corrugations or flanges that are difficult to produce by other methods to increase their rigidity.

Stamping parts production introduction

Through the use of dies and stamping equipment, we can complete mass production and batch processing, saving time and energy while completing a substantial reduction in capital. Universal stamping equipment, which can complete hundreds of times per minute, we have introduced foreign equipment to greatly increase stamping production capacity. After all, the parts are among the stamping equipment, and the pressure effect of the next forming step meets the market demand for mobility and mechanization. Generally, stamping plants choose stamping equipment to apply pressure to products when processing them. After precise setting, the standard of die production and processing will be more accurate. The life of the product is greatly extended.

The stamping processing method is called stamping, also known as cold stamping plate, stamping die and punching machine. It is the three major elements of stamping processing and is called the three elements of stamping. Under room temperature, a product of a certain shape and size is obtained by applying pressure to the plate using a die mounted on top of a punch to separate or deform it. This processing method is called stamping, also known as cold stamping.

 

 

custom stainless steel

Generally, it is not advisable to use highly elastic materials in the bending process for small stamping parts because the steel for stamping and bending needs to have good plasticity, low yield strength and low elasticity.

Steel with good plasticity is not easy to bend and crack; steel with lower yield strength and lower elasticity is unsuitable for bending. The strength and lower elasticity of the steel in the bending after forming the resulting rebound deformation are small, and it is easy to get the size of the precision bending shape.

Elongation class small stamping forming process should not be used poor plastic materials, stamping process of flaring, flanging, expansion, bending, external flanging, partial stretching belongs to the elongation class deformation; stretching, shrinkage, internal flanging, billet upsetting belongs to the compression class forming.

Elongation class forms because the deformation zone is mainly subject to positive stress, positive strain nature of tensile deformation, and deformation zone material is prone to excessive elongation. When this elongation reaches the ultimate elongation rate of the material, it will be very easy to produce rupture.

How to choose the material for precision stamping parts

The most commonly used materials in producing precision stamped parts are metallic materials (including ferrous and non-ferrous metals), but sometimes non-metallic materials are also used. Precision stamping parts manufacturers select the stamping materials for tensile parts pieces generally have the following principles.

The metal material must meet the requirements of the workpiece’s use performance; the stamping parts normally work in the machine or parts and have a certain service life.

The selected material must have good process performance; for any stamping parts, the selected material should be able to follow the requirements of its stamping process.

The selected material must have better economy; the material should be as inexpensive, convenient in origin and economical as possible to reduce the cost of the stamped parts on the premise of meeting the requirements of the use performance and stamping process.

auto car precision stamping

Design requirements for the structure of precision stamping parts

When designing the structure of precision stamped parts, the workpiece shape and inner hole should be rounded and no sharp corners are allowed. The minimum radius of rounded corners allowed is related to the material thickness. The punch diameter, long slot width and workpiece margin should not be too small. In precision stamped gears, the pitch width of the gear should not be less than 0.6t, and the top and root of the tooth shape should be rounded transition, and should not be sharp transition. The outer edge profile shape of precision stamped parts should have smooth transition as much as possible without abrupt change. When designing symbols or marks on the surface of the workpiece and making pressure cuts, the depth of pressure cuts shall not exceed 0.25t.

When designing the precision stamped parts, it should be ensured that the dimensional accuracy and surface roughness requirements are as low as possible under normal use, which is conducive to the interchangeability between precision metals, reducing scrap and ensuring stable quality of stamped parts.
The design of precision stamped parts should meet the use and technical performance of industrial products, and be easy to assemble and maintain.
When designing precision stamped parts, the existing equipment, process equipment and flow should be used as much as possible to process precision hardware stamped parts, and it should be conducive to prolonging the service life of stamping dies.
The design of the stamping parts should be conducive to improving the utilization rate of metal materials, reducing the variety of material specifications and minimizing the consumption of materials; using cheaper materials as much as possible and making the parts scrap-free and waste-free as much as possible.
The design structure of precision stamped parts should be reasonable and the shape should be simple, which is conducive to simplifying the die structure. The number of work sequences, i.e. completing the whole part with fewer and simpler stamping processes, reducing the processing by other methods, is conducive to the stamping operation and mechanized organization, and increasing the productivity of precision stamped parts.

Automotive terminals, precision wire speed terminals

The working process of precision stamping parts

It is a forming process to obtain a workpiece of the required shape and size (precision stamped parts) by applying an external force to plates, strips, pipes and profiles with presses and dies to produce plastic deformation or separation.

 

Inspection methods of precision stamping parts

Touch inspection

Wipe the surface of the extreme precision stamped parts with a neat sand cloth. The inspector should wear gloves and touch the surface of the precision stamped parts vertically along with the precision stamped parts. This kind of inspection method depends on the inspector’s working experience. If necessary, the abnormal area being explored can be polished with oil stone and certified in many aspects. Still, this kind of way is nothing more than a practical and rapid detection method.

oil stone grinding and polishing

First wipe the surface of the precision stamping parts with a clean emery cloth, and then polish the surface of the stamping parts with an oil stone (20×20×100mm or larger); places that are curved and cannot be polished with a relatively small oil stone (such as a half-round oil stone of 8×100mm) cannot be touched

Temperature Control Switch Product

The selection of oil stone particle size distribution lies in the surface condition (such as surface roughness, hot dip galvanizing, etc.). It is proposed to use coarse grit oil stone. Most of the oil stone grinding and polishing orientation along the vertical development very well cater to the surface of precision stamping parts; part of the area can also fill the horizontal grinding and polishing.

For soft diamond yarn grinding and polishing, clean the surface of precision stamping parts with a neat sand cloth. Use a soft sanding screen to polish along the vertical direction to all the surfaces of the precision stamping parts immediately, and all the black spots and embossed marks will be found very easily.

Wipe the surface of the precision stamping parts with a neat sand cloth for oil detection. Then use a neat soft brush to wipe the oil evenly on all the outer surfaces of the stamping parts in the same direction. Put the oiled stamped parts under strong light for inspection, and propose to put the stamped parts upright on the car body part. This method makes it very easy to detect the subtle black spots, deflated ponds and wavy lines on the stampings.

Visual inspection: The key to visual inspection is to detect the precision stamped parts’ abnormal appearance and macroeconomic shortcomings.

Tooling fixture inspection: The stamping parts are put into the tooling fixture, and the inspection of the stamping parts is carried out according to the actual operation regulations of the instructions for using the tooling fixture.

What method to choose for cleaning precision stamping parts

The different requirements of cleaning precision are divided into the general precision industrial cleaning agent, industrial cleaning agent, and ultra-precision industrial cleaning agent, three categories.

1, precision industrial cleaning includes cleaning various products during processing and production, cleaning various materials and equipment surfaces, etc., which can remove tiny dirt particles as a feature. 2, general industrial cleaning agents, including vehicles, ships, and aircraft surface cleaning, can only remove the relatively coarse dirt.

3, ultra-precision cleaning, including precision industrial production process of mechanical parts, electronic components, optical components and another ultra-precision cleaning, to clear off the very small dirt particles for the purpose.

The different cleaning methods can be divided into chemical cleaning and physical cleaning.

Relying on the role of chemical reactions, the use of chemical drugs * or other solvents to remove dirt from the surface of the object is called chemical cleaning. Such as the use of various inorganic or organic acids to remove rust, scale on the surface of the object, and oxidizing agents to remove the color of the surface of the object.

The use of mechanics, acoustics, optics, electricity, thermal and other principles, relying on external energy / amount of action, such as mechanical friction, ultrasonic cleaning, negative pressure, high pressure) for striking. Ultraviolet light, steam and other methods of removing dirt from the surface of the object is called physical cleaning.

How to prevent rust and corrosion of precision stamping parts

Precision stamping parts will use electroplating process, and the treatment methods are galvanization, copper plating, copper-nickel alloy, etc. Generally, customers who do not have high requirements for goods can consider galvanization. The advantage of galvanizing is that it is corrosion resistant and not easy to rust. The disadvantage is that it cannot maintain the gloss of the product surface for a long time.

Especially in a relatively wet and cold or black harsh natural environment (such as outdoor precipitation) or in a wet and cold intermediate area (such as next to a water pipe), the galvanized surface of the metal material will be accompanied by leaching and softening, and in the initial and early stages there will be situations such as skin whitening and blistering. Until the galvanized layer is completely leached out, it will stamp the surface of the parts and lose the maintenance of the galvanized layer. After losing the coating, the hardware configuration will rust, which will become more severe over time and then lose its ability to be applied.

When interrupting galvanization of stamping parts in cold, wet, and dark environments, a thicker galvanized surface is required. In addition to the thickened galvanized layer, a fully transparent coating is applied. Both of these will greatly increase the service life of the stampings.

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