Until now there has been no contact-free inspection system for rational and reliable detection of internal flaws in wire on the production line.
The Betriebsforschungsinstitut (BE), a German research institute, has therefore cooperated with Böhler Edelstahl GmbH (Böhler) and Krautkramer GmbH & Co (KK) to develop a test system that can remedy this deficiency.
The test system differs in principle from the methods used until now. The test detects internal and surface flaws in hot wire rods, is contact-free, and is carried out in the axial direction of the wires. Very high feed rates can be achieved in a continuous process.
The system works with EMATs (electromagnetic acoustic transducers). By using twodimensionally guided waves (rod waves), the flaws can be detected and localized in terms of their size and position. Moreover they can be differentiated by type with the help of a mode spectroscopic classification algorithm.
The procedure is currently being put into practice on an automatic pilot plant, which B6hler has tested and integrated into its in-house quality assurance system. The wire manufacturer is therefore given the opportunity of determining, and therefore improving, the quality of the wires during production. This industrial sector is therefore displaying considerable interest in the use of such a test procedure.
Users of wires employed for applications where safety is a prime consideration (e.g. engine manufacturers, who employ valve spring wires) can turn such quality information to considerable economic advantage, because quality control measures can serve to increase the service life of their products.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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