Imagine a potter who effortlessly molds clay with his expert hands. He applies a bit of pressure here, gently pulls there, and after a few minutes, the material has taken on an entirely new form. Flow-forming relies on a similar principle; it is a technology used to transform circular or tubular blanks into parts that are rotationally symmetric with varying wall thicknesses and complex geometries. Only instead of clay the raw material is steel. Flow-forming is used primarily to manufacture wheels and drive train components.
The process begins with using high-strength hot-rolled strip to make a blank in the form of a disk, tube or cup. The workpiece is clamped and rotated. Rollers then push against selected parts of the rotating workpiece, pressing it against the inner shape of the tool and stretching it in the axial direction. This is how a short, thick tube, for example, is transformed into a long, thin component with a superior surface quality. Such a part is also capable of bearing heavier loads, lasts longer, and can be manufactured with far greater precision than if produced by machining.
New testing facility enables more targeted research
This spring, thyssenkrupp Steel put a new flow-forming machine into commission. The new machine makes it possible to research material properties that are important for flow-forming and optimize these to meet customer requirements. Precision strip from the Precision Steel business unit can also be used as a reference material.
It means Application Technology in Duisburg is able to transfer the test results to simulations and develop new processes and grades – either for its own purposes or for a particular customer. The machine is suitable for processing ultra-high-strength steels and can be combined with other forming and heating technologies. As a result, certain components produced using flow-forming can be made up to 50 percent lighter. This innovative application will enable thyssenkrupp Steel to provide its customers in the automotive and machinery sectors with even better support in the future.