Issue 42

M. Kowalski, Frattura ed Integrità Strutturale, 42 (2017) 85-92; DOI: 10.3221/IGF-ESIS.42.10 85 Focused on Mechanical Fatigue of Metals Identification of fatigue and mechanical characteristics of explosively welded steel - titanium composite M. Kowalski Opole University of Technology m.kowalski@po.opole.pl A BSTRACT . Paper presents results of fatigue tests performed on S355J2 steel - titanium Grade 1 composite produced in explosive welding technology. Specimens were subjected to cyclic tension-compression loading with zero mean value and controlled force. Also mechanical properties were investigated. K EYWORDS . Welding; Explosive; Fatigue; Bimetal; Steel; Titanium. Citation: Kowalski, M., Identification of fatigue and mechanical characteristics of explosively welded steel - titanium composite, Frattura ed Integrità Strutturale, 42 (2017) 85- 92. Received: 31.05.2017 Accepted: 09.06.2017 Published: 01.10.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION echnology of the explosive welding is based on principles of joining dissimilar materials with the energy from explosive detonation. Phenomena of the explosive material joining was observed for the first time during the first world war, but from the commercial point of view technology became appreciated in the 1950's [7]. Explosive welding is defined as a solid state process. Bond between materials results from the impact effects during detonation. Stable joint between materials is attained if energy of the detonation cause hydrodynamic behavior of the material [7,8,16]. Characteristic feature of the interface lines is their wavy shape (Fig. 1). Bond and strength parameters are influenced by basic welding parameters: detonation velocity, standoff distance and welding angle [1,2]. Research on welding parameters and overall properties of multilayer material influenced on range of their industrial application. Especially in industry branches demanding universal properties of the construction materials for example: high strength and chemical resistance. At the present time explosively welded composites are used in industrial areas such as: chemical and nuclear engineering in example: tube sheets, heat exchangers. In the literature explosively welded multilayer materials are mainly investigated in terms of operational and design aspects like welding parameters and their impact on microstructure changes[2–4,6,9]. Influence of the heat treatment on overall properties of the material is also examined [5]. However, although the fatigue phenomenon which is very important from a design calculation and operational point of view [13, 14] is rarely investigated. T