Views: 1 Author: Site Editor Publish Time: 2022-07-25 Origin: Site
In the competition with non-ferrous alloys and polymer materials, iron and steel materials continue to give full play to their advantages of low price and mature technology. Through high strength and effective strengthening measures, their strength potential can be brought into full play. So far, they are still the most used materials in automobile production.
The lightweight of the car is to reduce the servicing quality of the car as much as possible on the premise of ensuring the strength and safety of the car, so as to improve the power of the car, reduce fuel consumption and reduce exhaust pollution. Experiments have shown that if the vehicle mass is reduced by half, the fuel consumption will also be reduced by nearly half. Due to the needs of environmental protection and energy conservation, the lightweight of cars has become the trend of the world's automobile development.
High strength steel plate
25% of the dead weight of a car lies in the body, and the lightweight of body materials plays an important role. In the 1990s, 35 major steel enterprises worldwide cooperated to complete the project of "ULSAB ultra light steel auto body". The research results of this subject show that 90% of the body steel plates use the high-strength steel plates that have been mass-produced (including high-strength, ultra-high strength and sandwich weight reduction steel plates), which can reduce the body weight by 25% without increasing the cost (taking the 4-door car as the reference), and the static torsional stiffness is increased by 80%, the static bending stiffness is increased by 52%, and the first body structural modulus is increased by 58%, meeting all the requirements of Collision Regulations. Of course, this is still a research achievement. The practical application of high-strength steel plates in car bodies has not reached such a high level. On the basis of ordinary if steel plate, high-strength if steel plate and bake hardening if steel plate have been developed successively, which improves the strength and dent resistance while maintaining high formability, creating conditions for the thinning of car body steel plate and the realization of lightweight.
The tensile strength of precipitation strengthened steel plate added with elements such as Ti, Nb and V is 500~750mpa, which can be used for wheels and other chassis parts.
Recently developed multiphase steels have considerable application potential. The strength grade of ferritic bainitic steel is 500MPa, that of duplex (DP) steel and phase transformation induced plasticity (trip) steel is 600~800mpa, and that of duplex (CP) steel is 1000MPa or higher. These steels also have good formability.
Tailored blank is a newly developed and applied lightweight technology for steel plate. In the aforementioned ULSAB body, 18 parts have adopted this technology.
In addition to the above purposes, the lightweight of the engine also involves the mass distribution of the whole vehicle (vehicle driving dynamics). When replacing a gasoline engine with a diesel engine, it often makes the engine heavier (solid structure, turbocharger, charge air cooler, fuel injection device, etc.), resulting in an increase in the axle load of the front axle, which destroys the balance of the whole vehicle. Therefore, the light weight of the car engine has become a problem that can not be ignored in the development of the whole vehicle.