Metal stamping processing is a forming processing method that relies on punches and stamping dies to apply external force to plates, strips, pipes and profiles to cause plastic deformation or separation, so as to obtain workpieces (metal stamping parts) of the required shape and size. Metal stamping and forging are both plastic processing (or pressure processing), collectively called forging. There are many kinds of blanks for metal stamping: ordinary hot-rolled and cold-rolled steel plates and steel strips; various types of stainless steel, such as: SUS201,202,SUS301,304,316,SUS430,439, etc.; brass, phosphor bronze and other copper alloys; copper, Pure aluminum and aluminum alloys, etc.; with the trend of lightweight automobile body, automobile stamping parts are made of various high-strength alloy steels.

       After the steel plate is hot rolled and cold rolled, the thickness of the plate gradually changes from thick to thin. Automobile body, chassis, fuel tank, radiator fins, boiler drum, container shell, motor, electrical iron core silicon steel sheet, etc. are all processed by automobile stamping molds. Metal stamping dies are also used in products such as instrumentation, household appliances, bicycles, office machinery, and household utensils.

      Compared with castings and forgings, metal stamping parts are thin, even, light and strong. Metal stamping can produce workpieces with reinforcing ribs, ribs, undulations or flanges that are difficult to manufacture by other methods to improve their rigidity. Due to the use of precision stamping dies, the precision of the workpiece can reach the micron level, and the repeatability is high, and the specifications are consistent. Holes, bosses, etc. can be punched out of metal.

       Cold-punched metal stamping parts generally no longer undergo cutting processing, or only a small amount of cutting processing is required. The precision and surface condition of hot stamping metal stamping parts is lower than that of cold stamping metal stamping parts, but still better than castings and forgings, with less cutting processing.

Metal stamping is an efficient production method. Using compound molds, especially multi-station progressive dies, multiple metal stamping processes can be completed on one punching machine, from strip uncoiling, leveling, punching to forming and finishing. Fully automated production. High production efficiency, good working conditions, low production cost, generally hundreds of pieces per minute can be produced.

Types of metal stamping process:

       Metal stamping is mainly classified by process, which can be divided into two categories: separation process and forming process. The separation process is also called punching, and its purpose is to separate the metal stamping parts from the sheet along a certain contour line while ensuring the quality requirements of the separated section. The purpose of the forming process is to make the sheet metal plastically deform without breaking the billet to make a workpiece of the required shape and size. In actual production, multiple processes are often applied to one workpiece. Blanking, bending, shearing, deep drawing, bulging, spinning, and correction are the main metal stamping processes.

       The surface and internal properties of metal stamping materials have a great influence on the quality of metal stamping products. The thickness of metal stamping materials is required to be accurate and uniform; the surface is smooth, without spots, scars, scratches, surface cracks, etc.; uniform yield strength , No obvious directionality; high uniform elongation; low yield ratio; low work hardening.

In actual production, process tests similar to the metal stamping process are commonly used, such as deep drawing performance test, bulging performance test, etc. to test the metal stamping performance of the material to ensure the quality of the finished product and a high pass rate.

      The precision and structure of the stamping die directly affect the forming and precision of the metal stamping parts. Stamping die manufacturing cost and life are important factors that affect the cost and quality of metal stamping parts. Stamping die design and manufacturing requires more time, which extends the production preparation time of new metal stamping parts.

Standardization and development of mold bases, mold bases, and guides. Simple stamping molds (for small batch production), composite molds, multi-station progressive molds (for mass production), and the development of rapid mold change devices, which can reduce metal stamping production preparations Workload and shortening of preparation time can make it suitable for reducing the workload and shortening of preparation time for metal stamping production, and enable the advanced metal stamping technology suitable for mass production to be reasonably applied to small batch and multi-variety production.

       In addition to forming thick plates with hydraulic presses, metal stamping equipment generally uses mechanical punching machines. With modern high-speed multi-station mechanical punching machine as the center, it is equipped with uncoiling, leveling, finished product collection, conveying and other machinery, as well as stamping die library and quick die change device. It can be controlled by computer program to form a high-productivity automatic metal stamping production line.

In the case of producing dozens or hundreds of metal stamping parts per minute, processes such as feeding, metal stamping, discharging, and waste discharge are completed in a short period of time, and personal, equipment and quality accidents often occur. Therefore, safe production in metal stamping is a very important issue.

Seek breakthroughs in the development of the metal stamping industry in case of obstacles

      According to statistics, in 2003, my country produced about 2.4 million tons/800 million pieces of automobile stamping parts, about 280,000 tons/1.9 billion pieces of metal stamping parts for motorcycles, and about 960,000 tons/710 million pieces of metal stamping parts for tractors and agricultural vehicles. 1 million tons/128 million pieces of hardware stamping parts for air conditioners and refrigerators. Experts in the industry predict that as the automobile industry, the largest user market in the metal stamping industry, continues to develop rapidly in the future, China’s metal stamping industry has ushered in a period of rapid development opportunities, but can it seize the opportunity to achieve new and faster development? Experts pointed out that there are still many obstacles and obstacles that need to be overcome and breakthroughs on the way forward.

Resistance 1: Low degree of mechanization and automation

      70% of the 680 metal stamping lines in the United States are multi-station presses, and 32% of the 250 production lines in Japan are multi-station presses. However, this type of large-scale multi-station punch presses that represent the current international level are rarely used in China. Many; small and medium-sized enterprises generally have backward equipment, high energy consumption materials, and serious environmental pollution; simple head forming equipment and heavy manual operation; fine blanking machines are expensive, 5-10 times that of ordinary punches, and the inability of most enterprises to invest hinders The promotion and application of fine blanking technology in China; hydroforming, especially internal high pressure forming, requires a large investment in equipment and it is difficult to start in China.

Breakthrough point: speed up technological transformation

       It is necessary to change the current backward situation in which most of the materials are loaded and unloaded by hand, combined with specific conditions, adopt new techniques, and improve the degree of mechanization and automation. The stamping of automobile body panels should be developed in the direction of single-machine connected automation, robotic hardware stamping production lines, especially large-scale multi-station punching machines. Strive to increase investment and accelerate the technological transformation of the automotive stamping production line, so as to reach the current international level as soon as possible. With the development of microelectronic technology and communication technology, there is a technical foundation for the automation and flexibility of sheet metal forming equipment. The development of digital flexible forming technology, hydroforming technology, high-precision composite forming technology, as well as profile bending technology and related equipment suitable for the new generation of lightweight body structures should be accelerated. At the same time, the old domestic equipment will be transformed to make it play a new production capacity.

Resistance 2: Low production concentration

     Many automobile groups are large and comprehensive, forming closed internal supporting facilities, leading to various types of hardware stamping parts of various enterprises, low production concentration, small scale, easy to cause low-level repetitive construction, difficult to meet specialized division of labor production, and weak market competitiveness; The motorcycle metal stamping industry is facing fierce market competition and is in a state of "superior but not winning, inferior but not the fittest"; head manufacturing companies are small but scattered, with a concentration of only 39.2%.

Breakthrough point: take the road of specialization

      Quickly change the current pattern of "large and complete" and "scattered and poor", separate the metal stamping parts from the automobile group as soon as possible, and establish several large metal stamping parts according to the large, medium and small categories of automotive stamping parts Manufacturing supply center and dozens of small and specialized parts factories. Only through the road of specialization can the metal stamping parts become bigger and stronger and become a competitive metal stamping parts supplier in the world.

Resistance 3: Insufficient self-sufficiency rate of metal stamping plates, unmatched varieties and specifications

       At present, my country's automobile sheet can only meet about 60%, and high-end automobile steel sheets, such as high-strength sheets, alloyed galvanized sheets, and ultra-wide sheets (above 1650mm), all rely on imports.

Breakthrough point: materials should be developed in coordination with the industry

      The variety of steel plates for automobiles should be more reasonable, and develop towards high-strength, high-corrosion-resistant and thin steel plates of various specifications, and improve the metal stamping performance. Aluminum and magnesium alloys have become rational materials for automobile lightweight, and expansion of their applications is already underway.

Resistance 4: Slow transformation of scientific and technological achievements, slow promotion of advanced technology

       In my country, many new metal stamping processing technologies started not too late, and some have reached the international advanced level, but it is often difficult to form productivity. There are not many applications of advanced metal stamping technology, and some are only in the trial stage, and the speed of absorption, transformation and promotion is slow. The low investment in technology development has led to slow mastery and application of advanced technology by enterprises, and insufficient development and innovation capabilities. The gap between SMEs in this area is even greater. At present, most domestic enterprises still use traditional metal stamping technology, and lack research and technical reserves for the forming technology needed for the next generation of lightweight automobile structures and materials.

Breakthrough: Take the road of combining industry, learning and research

      Compared with Europe, the United States, and Japan, the biggest gap between China is that there is no industry-university-research consortium, scientific research is difficult to expand, and the results cannot be transformed into productivity as soon as possible. Therefore, it is necessary to focus on large-scale development and industrialization projects, with universities and scientific research units as technical support, and enterprises as application bases, to form a joint entity of products, equipment, materials, and technologies to form a benign enterprise that can not only develop and innovate, but also rapidly industrialize cycle.

Resistance five: large, precision stamping dies rely on imports

At present, the materials, design and production of metal stamping dies cannot meet the needs of domestic automobile development, and the degree of standardization is still low, about 40% to 45%, while internationally, it is generally about 70%.

Breakthrough point: improve the level of informatization and standardization

It is necessary to transform stamping die enterprises with information technology, and the focus of development is to vigorously promote the integration of CAD/CAM/CAE technology, especially the computer simulation analysis and optimization technology (CAE) of the forming process. Accelerate the standardization process of my country's stamping dies, improve accuracy and exchange rate. Strive to achieve 60% coverage of standard stamping die parts in 2005 and over 70% in 2010 to basically meet market demand.

Resistance six: lack of professional talents

     High-quality talents with advanced design analysis technology and digital technology in the industry are far from meeting the needs of the rapid development of the metal stamping industry, especially in the motorcycle industry, there is a shortage of professional talents with hardware stamping knowledge, technology and skills and a large number of outflows. In addition, many joint ventures are designed by foreign parties and have design rights and investment rights. It is difficult for our metal stamping technicians to truly grasp the true meaning of the metal stamping process.

Breakthrough point: improve the quality of industry personnel

This is an urgent task, but also a long-term and systematic task. The revitalization of my country's hardware stamping industry requires a large number of high-level scientific and technological talents, a large number of entrepreneurs who are familiar with domestic and foreign markets, and have modern management knowledge and capabilities, and a large number of senior skilled personnel who have mastered advanced technology and technology. We must be willing to spend great effort to cultivate in a planned and hierarchical manner.

The rapid development of the metal stamping and forming user market has brought brand-new development opportunities to the stamping industry. Although there are still various resistances and obstacles on the development of the stamping processing industry, we always believe that these can not stop the hardware The pace of the stamping industry.