【正文】 ces, the prehensive impact of the technical level of the automotive industry, making aluminum and its alloys still can not be used in a large number of cars. Increase the variety, improve quality and reduce costs, has bee China39。s instability. Thus, high strength steel sheets are a difficult to form material. Thermoforming technology is a new type of highstrength stamping parts for the advanced manufacturing technology, can be used to form a strength of up to 1500MPa stamping parts, including the thermoforming process is stamping The frontier technology of the field can be widely used in the production of front and rear bumper, Apillar, Bpillar, Cpillar, roof structure, door interior plate, door anticollision beam and other ponents.2 light alloy material aluminum and aluminum alloyAluminum is the ideal choice for lightweight car, the resource is wide, lightweight, recycling, saving resources, absorbing impact energy, corrosion resistance, is the best overall performance of the basic material. The aluminum alloy used in the body is mainly deformed aluminum alloy, mainly AICuMg system (2000 series), AIMg system (5000 series), AIMgSi series (6000 series), AIMg ZnCu system. Which 2000 series and 6000 series is heat treatment can strengthen the alloy, while the 5000 series is heat treatment can not strengthen the alloy. The former through the coating drying process after the strength is improved, mainly for the body outside the board and other emphasis on strength, stiffness of the site, such as car cover, hood, lift rear door, front fender, etc .。s torsional stiffness even higher than the Grand Cherokee 45% Body carrying capacity of up to 2t or more. Ford39。s power, reduce fuel consumption and reduce exhaust pollution. Data show that if the car to reduce the quality of 10%, fuel efficiency can be increased by 6% to 8%, fuel consumption can be reduced by 6% to 10%. Fuel consumption decline, emissions also decreased, while resource utilization increased, extended life of the car, the use of performance has improved significantly. Car body quality accounts for about 50% of the quality of the vehicle, it is clear that the lightweight body for the vehicle lightweight play a pivotal role [1]. At present, the car body weight reduction has two main research directions: First, the use of lightweight materials。 Second, optimize the structure. Structural optimization potential space has been very small, the gradual use of lightweight new materials is the current body of one of the main means of lightweight.1 New high strength steelIn recent years, with the progress of metallurgical technology, on the basis of highstrength steel, with ultralow carbon as the basic characteristics, and gradually formed with deep drawing, high strength, baking hardening performance of new highstrength steel. At present, the use of highstrength automotive body is mainly sheet metal and pipe. Mainly: (1) BH steel (bake hardening steel). BH steel plate yield strength in the baking paint increased, without loss of formability under the premise of improving the antidepression, can reduce the steel plate, mainly for high strength and difficult to form parts, such as roof, Doors, luggage and other ponents, the main use of tensile strength of 340 ~ 390MPa BH steel plate. (2) RIP steel (phase change induced plastic steel). Mainly used for the collision must absorb more energy when the highstrength structural parts, such as body frame. (3) MS steel (martensitic phase steel). Used to hit the high impact parts, that is, in a very short collision deformation stroke to absorb a lot of energy, such as side crash protection. (4) boron steel. Used to require high strength and high degree of molding of parts, can minimize the quality. Such as A, B column reinforcement, etc. [2].Practice has proved that when the thickness of the steel were reduced , mm, the body weight loss were 6%, 12%, 18%. In terms of development trends, the use of new highstrength steel plate in the body is constantly thinning, while the body strength has increased, while increasing the safety of the car, reducing noise and vibration, improve fuel efficiency and reduce the overall quality of the car. The cost did not increase, while the acceleration, driving performance has improved. Whether from the cost point of view, or from the performance point of view, the new highstrength steel plate is to meet the lightweight body to improve the safety of the collision of the best materials. The proportion of new highst