Forming method capable of customizing strength of ultrahigh-strength steel hot-stamped parts

Abstract

The invention provides a forming method capable of customizing strength of ultrahigh-strength steel hot-stamped parts. The total electric energy input to steel plates by resistance heating is constant, different cross-sectional area portions are different in input energy in unit cross-sectional area, and heating temperatures are different, so that different strength is obtained. When the input energy in unit cross-sectional area is 825jmm<-2>, steel plates can be heated to a complete austenitizing temperature within 3s, and tensile strength of the steel plates after hot forming reaches above 1600MPa; when the input energy in unit cross-sectional area is lower than 688jmm<-2>, the heating temperature of the steel plates can be lower than the austenitizing temperature, and the tensile strength of the steel plates after hot forming is 600-700MPa. The cross-sectional areas and the sizes of the steel plates are designed according to strength requirements of different portions of components, hot-formed structural parts obtained after hot stamping have optimal strength and plasticity matching, overall weight of original parts is reduced, side-impact deformation resistance of automobiles is improved, and collision energy can be absorbed well.

Description

technical field [0001] The invention belongs to the technical field of hot stamping forming, and specifically relates to a non-isothermal resistance heating technology to realize the customized forming method of the strength change of the ultra-high-strength steel hot stamping parts of automobiles, and to realize the better comprehensive protection function of automobile security structural parts. Background technique [0002] Automobile structural parts need to have high strength to ensure collision safety, and at the same time, relatively low strength and relatively high toughness are required in specific parts to achieve high comprehensive performance to achieve energy absorption and better comprehensive protection functions. Existing automotive structural parts either have the same overall performance and cannot meet the actual use requirements, or can achieve variable strength of automotive structural parts but have great limitations. For example, some methods are conca...

AI Technical Summary

Problems solved by technology

Existing automotive structural parts either have the same overall performance and cannot meet the actual use requirements, or can achieve variable strength of automotive structural parts but have great limitations

For example, some methods are concatenated (see figure 1 ) to realize the performance difference of automobile structural parts, some can only realize the splicing of two kinds of strengths of automobile parts, and cannot realize the continuous change of the strength transition zone, some processes are complex, and there are performance concerns at the joint

Other methods, such as the technologies described in Chinese patent application numbers CN201110412533.7 and CN201120393429.3, change the shape and distribution of cooling water pipes in the mold (see figure 2 ) can realize the continuous change of the strength of automobile structural parts, but the realization method is relatively difficult, and only several kinds of variable-strength automobile structural parts can be manufactured, and the customization of the strength of structural parts cannot be fully realized

And mold manufacturing greatly increases the production cost of automotive structural parts

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