EuroWire May 2021

Technology News

Custom-tailored flat wire In the mass production of stamped and bent parts made of flat wire, there is price pressure, especially for larger series. While there are many ways of squeezing prices and saving costs, there is still potential for optimisation at the interfaces, according to Studer-Biennaform. As an example, a flat wire in AISI 302 Mo with a classic width/ thickness ratio had to be optimised. The initial wire was already designed for minimum work hardening. Strength, yield strength and elongation were good, as was the processability on the automatic machines. A brainstorming session with the customer via video call revealed that there was still “room for improvement” on the machines. The solution was tighter width and thickness tolerances to allow more precise wire guidance, higher speeds and shorter cycle rates, for a higher output rate. For this purpose, a skin-pass was added downstream of the previous multi-stage rolling stand, on a high-precision single stand. The thickness tolerance could therefore be reduced from ±10 micron to less than ±4 micron in mass production. The decrease of the wire width tolerance was achieved by adding an edge shaving step. The width tolerance was reduced from ±50 micron to a stable ±20 micron. The customer was able to validate the initial trial batch of 5kg flat wire within a short timeframe, as Studer’s in-house wire drawing

capability enabled it to offer a short lead time for the validation material. By analysing the entire value chain with all parties involved, Studer helped the customer to reduce the final cost of the parts.

Studer-Biennaform www.studersa.com

Representation of the cold-rolled flat wire

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May 2021