Georgsmarienhütte GmbH, Georgsmarienhütte:

A. Stüber, Dr. Eng., Development Manager

Saarstahl AG, Völklingen, Germany:

M. Waltner, Dr. Eng., Director of Technology and Nondestructive Testing

Saarstahl AG, Neunkirchen, Germany:

B. Bäcker, Service monitoring and quality assurance

BGH Edelstahlwerke GmbH, Siegen, Germany:

H. Jung, Material Science

voestalpine Stahl Donawitz GmbH & Co. KG, Austria:

H. Schifferl, Manger

Steel Institute VDEh, Düsseldorf, Germany:

I. Steller, Dr., Department of Technology and material research, ingo.steller@stahl-zentrum.de

The surface quality of steel bar and wire rod has a considerable influence on the quality of the final products, e. g. closed die forgings, cold forgings and bolts. With respect to the increasing customer requirements the current potentialsand limits of in-line testing for surface and internal discontinuities have been determined. State-of-the-art long products plants producing material for the production of advanced parts for the automotive industry are briefly observed in the paper. Scheme of eddy current testing with a concentric coil where signal of longitudinally oriented discontinuity is obtained is described and construction of eddy current device is shown. as well, scheme of flux leakage testing and corresponding device, testing method with rotating probes, ultrasonic testing device for wire are observed. Detectability for surface discontinuities on steel bar is analyzed for different materials with observing control method and with showing testing results. This report is the result of joint work within the Materials Committee of the German Steel Institute VDEh, technical committee for alloyed structural steels. Several large steel producers participated in this work: Georgsmarienhütte GmbH, Saarstahl AG, BGH Edelstahlwerke GmbH, voestalpine Stahl Donawitz GmbH & Co. KG.

1. Engineer, S. J.; Wieland, H.-J.:  stahl u. eisen 117 (1997) Nr. 3, S. 79/84.

2. Hradecny, T.; Deutsch, W. A. K.; Schuster, V.; Schneider, H.-J.; Koch, R.; Paulus, H.; Waltner, M.; Pe ter, C.; Beyer, K.; Lohmann, J. F.; Scholle, W.; Münch, G.: stahl u. eisen 124 (2004) Nr. 11, S. 119/28.

3. Sy, D.: Wirbelstromprüfung von Blankstahl in Stäben, Stabziehereien vereinigung e. V., Düsseldorf, 2001, http://www.blankstahl.org/stabziehereien/de/download/WirbelStromPruefung.pdf

4. Fehlerkatalog Stabstahl und Walzdraht, Stahlinstitut VDEh, Düsseldorf, 2011.