Abstract: A method of using a steel alloy, the steel alloy having a composition containing in mass %, 0.09-0.13% C, 0.10-0.50% Si, 1.10-1.80% Mn, max. 0.02% P, max. 0.02% S, 1.00-2.00% Cr, 0.20-0.60% Mo, 0.02-0.06 Al, 0.10-0.25% V, the balance iron and incidental impurities, includes the steps of forming a tube from the steel alloy; air hardening the tube in the presence of inert gas, and incorporating the tube in the production of a compressed gas container. The steel composition may also be used as material for producing formed structures in light weight steel construction.

Abstract: The invention relates to a method for forming a hub disk, in which a circular blank-like workpiece is placed in a flow-forming machine and fixed with at least one overarm support, an area of the outer contour of the overarm support corresponding to an area of the inner contour of a hub to be formed, the circular blank-like workpiece is rotated, at least one roller is infed and substantially radially moved in, a material flow taking place on the workpiece, and the radial moving in of the roller is ended when the distance between an area of the outer profile of the roller and the overarm support corresponds to the desired thickness of the hub wall and during the infeeding of the roller the workpiece is initially contacted by a cutting or separating edge of the roller and the material flow along the roller and therefore the axial length of the hub is limited by the roller geometry.