Fatigue strength of thermal cut edges—influence of ISO 9013 quality groups

  • Paul Diekhoff
  • J. Hensel
  • Th. Nitschke-Pagel
  • K. Dilger
Research Paper


The use of high strength steels has gained importance due to the interest in effective light steel constructions. Besides the well-designed weld seams, free cutting edges gain technical and economic relevance as locations for potential fatigue cracks. In this investigation, fatigue tests were carried out on 8-mm- and 20-mm-thick samples with a minimum yield strength ranging from 355 to 960 MPa at a stress ratio of R = 0.1. The cutting methods used were oxygen, plasma, and laser cutting. The surface roughness, hardness profile, and residual stresses were measured to classify the specimens into quality groups according to ISO 9013. Most of the specimens are classified in the quality groups 2 and 3. A slight tendency can be seen that the fatigue strength decreases with an increasing roughness value. Increasing local hardness values at the cut edges also have a minor negative influence on the fatigue strength. No positive impact was observed for increasing tensile strength on the fatigue strength. With higher surface roughness values, larger notches exist, the crack initiation starts early, and the fatigue strength decreases.


Thermal cutting Fatigue strength Surface roughness Cut edge Surface quality 


Funding information

The presented investigations were supported by the Arbeitsgemeinschaft industrieller Forschungsvereinigungen (AiF) in the project 18.789N “Bedeutung der Qualitätsmerkmale freier Schnittkanten nach DIN EN 1090 für deren Schwingfestigkeit unter Berücksichtung von Eigenspannungen.”


  1. 1.
    DIN EN 1090 (2017) Execution of steel structures and aluminum structures – Part 2: technical requirements for steel structures; German and English version EN 1090-2Google Scholar
  2. 2.
    DIN EN ISO 9013 (2014) Thermal cutting – Classification of thermal cuts - Geometrical product specification and quality tolerances (ISO/DIS 9013). Beuth Verlag, ‎BerlinGoogle Scholar
  3. 3.
    Grubisic V, Sonsino CM (1992) Influences of the fatigue strength of forged components, special print VDI-Z Bd 134, (in German)Google Scholar
  4. 4.
    Fuchs HO, Stephens RJ (1980) Metal fatigue in engineering. John Wiley, New YorkGoogle Scholar
  5. 5.
    Hempel M (1962) Fatigue behavior of the materials. VDI-Z. 104. 27, 1362–1377, (in German)Google Scholar
  6. 6.
    DIN EN ISO 18265 (2013) Testing of metallic materials - Conversion of hardness values. CEN-CENELEC Management Centre, BrusselsGoogle Scholar
  7. 7.
    Radaj D, Vormwald M (2007) Fatigue strength - fundamentals for engineers, 3. Auflage, Springer Verlag. (in German)Google Scholar
  8. 8.
    Dahl W (1974) Fundamentals of strength and fracture behavior. Verlag Stahleisen, Düsseldorf (in German)Google Scholar
  9. 9.
    Wu Z, Huang Y (2017) Mechanical behavior and fatigue performance of austenitic stainless steel under consideration of martensitic phase transformation. Mater Sci Eng A 679:249–257CrossRefGoogle Scholar
  10. 10.
    FKM-Guidelines (2002) Calculated proof of strength for machine components made of steel, cast iron and aluminum materials, 4. Ausgabe. VDMA-Verlag, Frankfurt/MGoogle Scholar
  11. 11.
    Sperle J-O (2007) Influence of parent metal strength on the fatigue strength of parent material with machined and thermally cut edges. IIW Document XIII-2174-07. International Institute of Welding, ParisGoogle Scholar
  12. 12.
    Remes H, Korhonen E, Lehto P, Romanoff J, Niemelä A, Hiltunen P, Kontkanen T (2013) Influence of surface integrity on the fatigue strength of high-strength steels. J Constr Steel Res 89(9):21–29CrossRefGoogle Scholar
  13. 13.
    Stenberg T, Lindgren E, Barsoum Z, Barmicho I (2016) Fatigue assessment of cut edges in high strength steel - influence of surface quality. KTH Royal Institute of TechnologyGoogle Scholar
  14. 14.
    Hobbacher A (2009) IIW recommendations for fatigue design of welded joints and components WRC. Welding Research Council Bulletin, WRC 520, LondonGoogle Scholar
  15. 15.
    DIN EN 10025-4 (2011) Hot rolled products of structural steels – Part 4: technical delivery conditions for thermomechanical rolled weldable fine grain structural steels; German version EN 10025-4Google Scholar
  16. 16.
    DIN EN 10025-3 (2011) Hot rolled products of structural steels – Part 3: technical delivery conditions for normalized/normalized rolled weldable fine grain structural steels; German version EN 10025-3Google Scholar
  17. 17.
    DIN EN 10025-5 (2011) Hot rolled products of structural steels – Part 5: technical delivery conditions for structural steels with improved atmospheric corrosion resistance; German version EN 10025-5Google Scholar
  18. 18.
    DIN EN ISO 4288 (1996) Geometrical Product Specifications (GPS) – Surface texture: Profile method – Rules and procedures for assessment of surface texture (ISO 4288)Google Scholar
  19. 19.
    DIN EN ISO 6507-1 (2016) Metallic materials – Vickers hardness test – Part 1: test method (ISO/DIS 6507-1)Google Scholar
  20. 20.
    DIN 50100 (2015) Load controlled fatigue testing – Execution and evaluation of cyclic tests at constant load amplitudes on metallic specimens and componentsGoogle Scholar

Copyright information

© International Institute of Welding 2019

Authors and Affiliations

  1. 1.Institute of Joining and WeldingUniversity of BraunschweigBraunschweigGermany

Personalised recommendations