3. Mold design for hot stamping of high strength sheet
First, select the mold material. Compared with cold stamping, hot stamping has stricter requirements on mold materials, and it is required to have better wear resistance, fatigue, high hardness and strength, and to ensure the dimensional accuracy of the formed parts. Under normal circumstances, when selecting the mold material, it should be based on the heating temperature of the mold, and combined with hot forging hot work die steel, select the appropriate mold material.
Second, the die and punch of the mold are designed. Due to the thermal expansion and contraction, there is a certain error between the size of the parts obtained during press forming and the size of the final part. Therefore, in order to ensure the accuracy of the part size, when hot-stamped parts are to be formed, Considering the influence of thermal expansion and contraction, the dimensions of the die and the punch are scientifically designed.
Finally, design the cooling mechanism. In the selection of the cooling mechanism of the part after hot stamping, it is necessary not only to ensure sufficient cooling rate of the part, so that the austenite can be rapidly transformed into martensite, thereby ensuring the strength of the part, and also must prevent the part and the mold. Cracking occurs due to excessive cooling rate. In general, the parts after hot stamping are cooled by taking the cooling water into the mold.
In the future, people's requirements for automobiles will be higher, especially in terms of safety, comfort, energy conservation, environmental protection, etc. To achieve this goal, it is a kind of high-strength steel stampings on the car body. A good way. High-strength steel can reduce the weight of auto parts by reducing the thickness of the steel parts, and achieve the goal of reducing the weight of the vehicle body, thereby achieving energy saving and emission reduction of the vehicle. In addition, the high strength of the high-strength steel can improve the safety of the vehicle. The use of high-strength steel for the manufacture of automotive parts requires the use of hot stamping technology. Under the current situation, it is extremely important and realistic to further strengthen the research and development of hot stamping forming technology.