Welding Residual Stresses in Tubular Joints

Abstract:

In spite of an increased awareness of welding residual stress threat to structural integrity, the extent of its influence on fatigue especially under multiaxial loading is still unclear and is a matter of debate. One important reason for this lack of clarities is that the determination of the initial welding residual stress field in welded structures even at the fatigue crack initiation sites is difficult and requires complementary instruments. Since the fatigue crack initiation in sound welds almost always occurs on the surface, the determination of surface residual stresses could increase the awareness of the extent of their threat to the structural safety. In this paper the development of residual stresses in different TIG-welded tubular specimens out of S355J2H and S690QL steel is studied and compared. The mechanisms of the development of residual stresses based on heat input and cooling rate are discussed. The welding parameters and thus heat inputs are varied and the mechanisms leading to different residual stress states are investigated. X-ray method was used for residual stress state characterization.

• Periodical: Materials Science Forum (Volumes 768-769)
• Pages: 605-612
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.768-769.605
• Online since: September 2013
• Authors: Majid Farajian, Thomas Nitschke-Pagel, Klaus Dilger
• Keywords: Fatigue, In Situ, Residual Stress, Tubular Joint, Welding

References

[1] Hobbacher A., Recommendations for Fatigue Design of Welded Joints and Components, IIW-Document, XIII-2151-07 / XV-1254-07, (2007).

DOI: 10.1007/978-3-319-23757-2_8

[2] EN 1993-1-9 (Eurocode 3): Design of Steel Structures, Part 1. 9: Fatigue strength of steel structures, CEN, Brussels, Belgium, (2005).

[3] Siljander. A, Kurath. P, Lawrence. F. V, Non-proportional fatigue of welded structures, Advances in Fatigue Lifetime Predictive Techniques, ASTM STP 1122, Edited by M. R. Mitchell and R. W. Landgraf, Philadelphia, (1992), pp.319-338.

DOI: 10.1520/stp24166s

[4] Sonsino. C. M, Overview of the state of the art on multiaxial fatigue of welds, Multiaxial fatigue and fracture ESIS publication, vol. 25, 1999, pp.195-218.

DOI: 10.1016/s1566-1369(99)80016-8

[5] Maddox S. J, Sonsino C. M, Multiaxial fatigue of welded structures-problems and present solutions, Manuel de Freitas, Editor, Proceedings of the Sixth International Conference on Biaxial / Multiaxial Fatigue and Fracture, Lisboa, vol. II, 2001, pp.3-16.

DOI: 10.1046/j.1460-2695.2001.00393.x

[6] Farajian M. Stability and Relaxation of Welding Residual Stresses, PhD Dissertation, TU Braunschweig, ISBN 978-3-8322-9861-6, (2011).

[7] Wohlfahrt H., Die Bedeutung der Austenitumwandlung für die Eigenspannungsentstehung beim Schweißen, The Significance of Austenite Transformation for the Development of Welding Residual Stresses, Härterei-Technische-Mitteilung, 41, 1986, pp.248-257.

DOI: 10.1515/htm-1986-410507

[8] Nitschke-Pagel Th., Wohlfahrt H., The generation of residual stresses due to joining process, Residual Stresses-Measurement, Calculation and Evaluation, Ed. Hauk V., Hougardy H. and Macherauch E., DGM-Informationsgesellschaft Verlag, 1991, pp.121-134.

[9] Jones W. K. C., Alberry P. J. A model for stress accumulation in steels during welding, International Conference on Residual Stresses in Welded Construction and Their Effects, London, TWI, 1977, pp.15-26.

[10] Seyffarth P., Meyer B., Scharff A., Großer Atlas Schweiß-ZTU-Schaubilder, DVS-Verlag GmbH, (1992).