Vehicle Hat Member with Localized Hardness Gradient for Crash Energy Absorption

The patent applies local quality by creating a tailored blank with spatially varying material properties. Different regions of the steel plate are assigned different tensile strengths (e.g., 1500 MPa in high-strength regions, 1000 MPa in low-strength regions) to achieve optimal balance between overall strength and local toughness. This allows the structure to have high strength where needed while maintaining toughness in other areas for impact resistance.

The patent applies preliminary action by pre-forming the tailored blank with non-uniform material properties before the final forming process. The blank is prepared in advance with regions of different strengths through controlled rolling or other material modification techniques, so that when the blank is subsequently formed into the final part, the desired strength distribution is already in place without requiring complex post-processing or assembly operations.

The patent applies parameter changes by systematically varying the material parameters (tensile strength, hardness) across different regions of the blank. By controlling the rolling force, temperature, and passage through rollers during blank preparation, precise strength distribution is achieved. The material parameters are adjusted in a controlled manner to create the desired gradient or step-wise variation in strength across the blank, enabling precise control of where high-strength and low-strength regions will be located in the final part.