Stamping is a forming processing method that relies on presses and dies to apply external force to plates, strips, pipes and profiles to cause plastic deformation or separation, so as to obtain workpieces (stamping parts) of the required shape and size. Stamping and forging are both plastic processing (or pressure processing), collectively known as forging. The blanks to be stamped are mainly hot-rolled and cold-rolled steel plates and strips. Of the world's steel, 60 to 70 percent are plates, most of which are stamped into finished products. The car body, chassis, fuel tank, radiator fins, boiler steam drum, container shell, motor, electrical iron core silicon steel sheet, etc. are all stamped and processed. There are also a large number of stamping parts in products such as instruments, household appliances, bicycles, office machinery, and living utensils. Stamping processing is the production technology of using the power of conventional or special stamping equipment to directly subject the sheet metal to the deformation force and deform in the mold, so as to obtain product parts with a certain shape, size and performance. Sheet materials, molds and equipment are the three elements of stamping processing. According to the stamping processing temperature, it is divided into hot stamping and cold stamping. The former is suitable for sheet metal processing with high deformation resistance and poor plasticity; the latter is carried out at room temperature and is a commonly used stamping method for thin plates. It is one of the main methods of metal plastic processing (or pressure processing), and it also belongs to material forming engineering technology.
Today's high-strength steel and ultra-high-strength steel have achieved the lightweight of vehicles and improved the collision strength and safety performance of vehicles. Therefore, they have become an important development direction of automotive steel. However, as the strength of the sheet metal increases, the traditional cold stamping process is prone to cracking during the forming process, which cannot meet the processing requirements of high-strength steel plates. Under the condition that the forming conditions cannot be met, the hot stamping forming technology of ultra-high-strength steel plates has been gradually studied internationally. This technology is a new process that integrates forming, heat transfer and structural phase transformation. It mainly uses the characteristics of increased plasticity of sheet metal and decreased yield strength under high-temperature austenite state, and the process of forming through molds. However, thermoforming requires in-depth research on process conditions, metal phase transition, and CAE analysis technology. This technology is monopolized by foreign manufacturers and has slow domestic development. In the past, in the production of deep-drawing or re-punching workpieces, everyone believed that the pressure-resistant (EP) lubricant was the best choice for mold protection. Sulfur and chlorine EP additives have been mixed into pure oil to increase the life of the mold has a long history. However, with the emergence of a new metal—high-strength steel and strict environmental protection requirements, the value of EP oil-based lubricants has been reduced or even lost.
