Influence of Milling and Abrasive Waterjet Cutting on the Fatigue Behaviour of DP600 Steel Sheet

Abstract:

Theobservation of cracks in mechanical parts shows that cracks often initiate oncutting edges. A lot of effort has been done to developing theories to predictfatigue behaviour of welds. However for the cut-edges available data is veryscarce on the fatigue behaviour. Thispaper presents theresults obtained in fatigue tests on DP600 dual-phase steel sheet specimens, underthree types of cutting edges processes: milling with two cutting parameters andabrasive waterjet cutting. The tests were carried out using smooth specimens (K_t=1)and with a fatigue constant amplitude loading with R=0.1. Surface roughness andresidual stresses induced by these different cutting conditions were measuredand analysed. It was found that the fatigue strength of the abrasive waterjetcutting specimens was smaller than the predicted fatigue strength of themilling specimens and these may be attributed to the surface roughness inducedby the cutting process. Finally failure mechanisms were studied with the scanningelectron microscope (SEM) at fracture surfaces, including the identification ofthe fatigue crack initiation region. It was also observed that fatigue crackinitiation takes place on the cut-edges.

• Periodical: Advanced Materials Research (Volumes 891-892)
• Pages: 1761-1766
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.891-892.1761
• Online since: March 2014
• Authors: Pedro Duarte, Virgínia Infante*, Manuel de Freitas
• Keywords: Abrasive Waterjet Cutting, DP600, Fatigue, Milling, Residual Stress, Roughness

References

[1] S.J. Maddox, Fatigue behavior of welded structures, Ed. Abington Publishing, Cambridge, UK, (2000).

[2] C.M. Branco, A.A. Fernandes, P.T. Castro, Fadiga de Estruturas Soldadas, second ed., Ed. Fundação Calouste Gulbenkian, Lisbon, Portugal, (1999).

[3] D. Radaj, Design and Analysis of Fatigue Resistant Welded Structures, Ed. Abington Publishing, Cambridge, UK, (1994).

[4] F. Meurling, A. Melander, J. Linder, M. Larsson, The influence of mechanical and laser cutting on the fatigue strengths of carbon and stainless steel sheets, Scandinavian Journal of Metallurgy, 2001, 30, 309 - 319.

DOI: 10.1034/j.1600-0692.2001.300506.x

[5] F. Meurling, A. Melander, J. Linder, Comparison of the fatigue characteristics of punched and laser cut stainless steel sheets, Fatigue Design, 1998, vol. 1, 351 - 362.

[6] D. Taylor, Geometrical effects in fatigue: a unifying theoretical model, International Journal of Fatigue, 1991, vol. 21, 413 - 420.

DOI: 10.1016/s0142-1123(99)00007-9

[7] D. Arola, M. Ramulu, Material removal in abrasive waterjet machining of metals. A residual stress analysis, Wear, 1997, vol. 211, 302 - 310.

DOI: 10.1016/s0043-1648(97)00131-2

[8] ASME B46. 1-(1995).