Fatigue strength of marked steel components - Influence of durable marking methods on the fatigue strength of steel components

According to EN 1090-2, steel components have to be identifiable and traceable throughout the whole production chain. The choice of identification method is not specified consistently in international rules and standards. In terms of durability and liability, markings should be resistant to particular fabrication processes such as sandblasting, hot-dip galvanizing or coating. The methods are hard stamping, scribing, plasma marking and needling. The effect of the notch caused by the marking process on the fatigue strength of the components has not yet been investigated in detail. As a result, a classification of the notch details in the European detail categories of EN 1993-1-9 is, in principle, impossible. For these reasons, the influence of durable marking methods on the fatigue strength of steel components needs to be clarified by experimental fatigue tests currently being performed at the Institute for Metal and Lightweight Structures, University of Duisburg-Essen. Part of this investigation involves examining the different surface conditions of hard-stamped, scribed, plasma-marked and needled specimens. The experimental investigations are being carried out considering two different steel grades, S355J2 and S460N, and three different steel plate thicknesses, 15, 25 and 40 mm.