Study On The Application Of Hot Stamping Process In Automobile Lightweight

As the energy crisis, traffic safety and environmental pollution getting worse,energy saving, safety, and environmental protection have become the three trends inthe development of the world automobile industry in the21st century. Automobilelightening technology is one of the effective ways to achieve these goals. Bodystructure design and optimization by using lightweight materials are two effectiveways. Lightweight materials include new type lightweight materials and (ultra) highstrength steel. On one hand, new type lightweight materials, such as aluminum alloy,titanium alloy, carbon fiber, provide a broad space for automobile lightweighttechnology development; on the other hand, as the hot stamping process emerging,ultra high-strength steel, the tensile strength of which is above1500Mpa, is becomingwidely used in the car body.This article mainly includes the following contents:(1) It is illustrated that the basic requirements for cooling system design of hotstamping die. On the one hand, base on theory of heat transfer and elastic-plastic, it isestablished that the mathematical expression between the number and diameter ofcooling pipes, the mathematical expression of cooling pipe spacing; on the other hand,simplifying cooling pipes mechanical model to simply-supported beam, themathematical expression for the distance of die surface and cooling pipe is established.Base on mathematical expression given above, the hot stamping die for the "ZQ" cardoor anti-collision beam is designed.(2) Base on the LS_DYNA software, bulk flow method is introduced in themodeling of cooling system of hot stamping die, innovatively. It is established of themodel of workpiece, hot stamping die and cooling water. The thermo-mechanicalcoupling simulation is carried out between forming and cooling stages, taking a "U"type part of door anti-collision beam as sample. the study is carried out on effects ofprocess parameters in hot forming process, such as cooling water flow rate, coolingpipeline diameter, initial temperature of the blank, mold temperature changing,stamping speed and so on. And according to temperature distributions at the end offorming and pressure quenching stage, the optimization is carried out on coolingsystem layout and process parameters.(3) Referencing on door stiffness testing regulations at home and abroad, comparative study is carried out on static rigidity and the impact energy-absorptionproperties of door anti-collision beam made by cold pressing and hot stamping.Studies have shown that hot forming anti-collision beam has excellent static bearingcapacity and dynamic impact energy absorption performance. Finally, It verifies theadvantages of hot stamping process in improving vehicle safety, reducing body weight.Therefore, hot stamping technology is of great significance for the development ofautomobile lightweight.This article takes the "ZQ" car door anti-collision beam for the study, anddesigns a special mold for hot forming and experiment is carried out. It verifies thevalidity of cooling system design method and bulk flow method. This thesis is theapplication of CAE study, in the early development stage of hot stamping die, it iseffective in shortening mold development cycle and reducing development costs byusing cooling system design method and bulk flow method mentioned above.