Joint-site structure for components to be connected by means of overlap friction welding, and method for connecting components by means of friction welding

A method for connecting first and second components using overlap friction welding comprising:

• providing first and second components having first and second ends, respectively, wherein the first end has a first thin-walled coaxial insertion region and the second end has a second thin-walled coaxial insertion region, wherein the first thin-walled coaxial insertion region has at least one step having a smaller diameter as compared with an outside diameter of the first component, and wherein the at least one step forms a ring-shaped face surface set back axially relative to a first face surface of the first component and is configured as a joining surface for friction welding;
• first, inserting the first and second thin-walled coaxial insertion regions of the first and second components, respectively, axially into one another until the first face surface of the first component abuts against a joining surface of the second surface, wherein a radial gap forms between mantle surfaces of the first and second thin-walled coaxial insertion regions that engage into one another;
• subsequently putting at least one of the first and second components into rotation and pressing the first and second components against one another by an axially acting process force until material of at least one of the first and second components softens;
• wherein the at least one step is provided with a radial undercut so that on a face side of a region the at least one step is unchanged in diameter and forms a radial support ridge connected with the first component by way of a heat throttle having a reduced cross-section;
• wherein the at least one step has a length designed so that at a beginning of a friction welding process, a wide axial ring gap is present between the first face surface of the first component and a second face surface of the second component lying opposite in an identical radial position;
• and
• wherein the wide axial ring gap is reduced to a minimum width during action of the axially acting process force on the first and second components at an end of the friction-welding process.