Patent ID: 11913101
Assignee: BENTELER STEEL/TUBE GMBH
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  F  Y | IPC B  C  F

Claim 0:
1. Tubular element for a gas pressure container of an airbag system of a motor vehicle, wherein the tubular element (10) comprises at least two first length sections (100, 101) and at least one recess (11) extending in the circumferential direction, characterized in that:
the tubular element (10) comprises at least one second length section (102) formed by the recess (11) extending over at least part of the circumference of the tubular element (10),
the second length section (102) lies between the at least two first length sections (100, 101),
in each of the at least two first length sections (100, 101) the outer radius (A1) of the tubular element (10) is greater than the smallest outer radius (A2) of the at least one second length section (102),
the tubular element (10) comprises a tensile strength of >920 MPa,
the wall thickness (W2) of the tubular element (10) in the at least one second length section (102) is thicker than or equal to the wall thickness (W1) in the at least two first length sections (100, 101) of the tubular element (10),
the degree of reduction of the outer radius (A2) in the recess (11) lies in the range from 5 to 35% relative to the outer radius (A1) of the at least two first length sections (100, 101),
between one of the at least two first length sections (100, 101) and an adjacent second length section (102) a tapering third length section is formed, in which the outer radius (A3) of the tapering third length section decreases from the outer radius (A1) of at least one of the at least two first length sections (100, 101) to the axially outer edge of the recess (11), and the tapering third length section has a length of at most 2.5 times the wall thickness (W1) in the at least two first length sections (100, 101), and
the tubular element (10) consists of a material which, in addition to iron and impurities resulting from the melting process, comprises the following alloying elements in the ranges indicated in weight percent:, C
0.05-0.2%   

Si
≤0.9% 

Mn
0.2-2.0% 

Cr
0.05-2% 

Mo
<0.5%

Ni
<1.0%

Nb
0.005-0.10%    

Al
<0.07% 

Ti
 <0.035% and

B
<0.004%.