Fatigue assessment of cut edges in high strength steel - Influence of surface quality
(English)Manuscript (preprint) (Other academic)
The influence of surface roughness on the fatigue strength in high strength steels which was cut using different cutting processes were studied. Fatigue testing was conducted on S700 and S960 material of different plate thicknesses cut in dog bone specimens using oxygen, plasma, laser and waterjet cutting. The surface roughness was measured on all specimens and residual stress measurements were conducted. Estimations of the fatigue strength were made using the measured surface roughness and the ISO 9013:2002 standard for thermal cutting quality tolerances. The testing proved a 15-70% increased fatigue strength compared to the estimation, proving a weak connection between the surface quality levels in ISO 9013:2002 and the fatigue test results. Different codes and design recommendations (IIW, EC3 and EN 13001) for fatigue strength of cut surfaces were compared with the fatigue test results which clearly showed an increased fatigue strength with enhanced quality and steel grades and where the codes and design recommendations do not allow for any fatigue strength improvement with improved quality and increased strength.
High Strength Steels, Fatigue assessment, Thermal Cutting, Oxygen cutting, Plasma cutting, Laser cutting, Waterjet cutting, Quality, Surface roughness, Welded structures, Cut edges
Research subject Vehicle and Maritime Engineering; Solid Mechanics; Production Engineering; Machine Design
IdentifiersURN: urn:nbn:se:kth:diva-188541OAI: oai:DiVA.org:kth-188541DiVA: diva2:936239
QC 2016060132016-06-132016-06-132016-06-13Bibliographically approved