High strength high slenderness part having excellent energy absorption

Abstract

A high strength, high slenderness structural part having excellent energy absorption properties in the case of an impact is provided. In particular, a structural part for use in an automotive vehicle is provided. The structural part has an ultimate tensile strength higher than 1000 MPa, a yield strength to ultimate tensile strength ratio higher than 0.85, a bending angle normalized to 1.5 mm thickness higher than 55° and a slenderness ratio higher than 10.

What is claimed is: 
     
         1 - 5 . (canceled) 
     
     
         6 : A part comprising and made from materials having an ultimate tensile strength after forming higher than 1000 MPa, wherein:
 the ratio between the Yield Strength YS and the ultimate tensile strength UTS of the materials is higher than 0.90;   the bending angle normalized to 1.5 mm thickness of the materials is higher than 55°; and   the slenderness ratio of the part is higher than 10.   
     
     
         7 : The part as recited in  claim 6  wherein the bending angle normalized to 1.5 mm thickness of the materials used to manufacture said part is higher than 70°. 
     
     
         8 : The part as recited in  claim 6  wherein the part is made of several individual subparts assembled together by welding and wherein a hardness drop in heat affected zones associated with the welding is less than 100 Hv. 
     
     
         9 : The part as recited in  claim 6  wherein the material to manufacture said part is steel. 
     
     
         10 : The part as recited in  claim 9  wherein at least one portion of the part is made by hot stamping of the steel.