Analysis of experimental data on the behavior of steel S275JR – Reliability of modern design Josip Brnic a,⇑ , Goran Turkalj a , Jitai Niu b , Marko Canadija a , Domagoj Lanc a a Department of Engineering Mechanics, Faculty of Engineering, University of Rijeka, Vukovarska 58, 51000 Rijeka, Croatia b Harbin Institute of Technology, 92 West Dazhi Street, Harbin, China article info Article history: Received 18 October 2012 Accepted 17 December 2012 Available online 28 December 2012 Keywords: Material properties Elevated temperatures Charpy impact energy Fracture toughness assessment abstract The purpose of this paper is to present the research results concerning S275JR (1.0044) steel material behavior loaded at room and elevated temperatures as well as result analysis in relation to its possible application. In this way, the data will be added to the existing data pool of considered material so as to be more readily available to other researchers and interested parties. Tensile testing of round speci- mens and Charpy impact testing of single edge notch bend specimens was conducted at different temper- atures. On the basis of mentioned research, the following material properties were determined: ultimate tensile strength (r m ), 0.2% offset yield strength (r 0.2 ), modulus of elasticity (E) and Charpy impact energy (CVN). Also, short-time creep behavior was examined. Test results are presented in the form of engineer- ing stress–strain diagrams, the curves of the temperature dependence on material properties as well as creep curves. At the end of this paper, an assessment of fracture toughness based on the Charpy impact energy is given. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction 1.1. Structure design against failure An engineering structure is designed, manufactured, main- tained and controlled in order to guarantee that it does not con- tain any failure and that it can serve for the purpose for which it is intended. Serving for the purpose for which structure was de- signed; structure lifetime predictions and safety during service life are key questions regarding its quality and reliability. The knowledge of material properties is of great signiﬁcance for the designer. The structure elements should be made of such materi- als whose properties are suitable for the operating conditions. Also, the designer must be familiar with the effects occurring as a result of manufacturing processes and the heat affecting the properties of the material. The selection of the proper material is one of the most difﬁcult tasks for any engineer to master. Therefore, while selecting the material, the common factors like material availability, suitability for service conditions and, of course, the cost of the material should be considered. Physical, chemical and mechanical properties are properties which deter- mine the utility of the material. The analysis of failures in engineering structures is of utmost importance in an engineering approach to determining why and how an engineering compo- nent has failed. This means that the particular failure has its cause of origin and the form of its expression. The mentioned analysis is a very important aspect of engineering because it deals with the determination of failure causes of the engineering struc- ture. In literature, these causes are usually speciﬁed and accord- ingly, offer an answer why certain component has failed. Also, in engineering practice many of failure modes have been ob- served which gives an answer to the question how the compo- nent has failed. The knowledge and understanding of the root causes of failures provide a basis for improvements in design, manufacture and the use of structures, preventing us so from repeating similar mistakes in the future. General failure causes should be mentioned: structural loading, corrosion, wear as well as some of latent defects. Common causes of failure may include: misuse (or abuse), design errors, improper material, assembly er- rors, improper maintenance, manufacturing defects, unforeseen operating conditions, the transition of temperature effect, inade- quate control, etc. [1,2]. The misuse means that the structure is subjected to conditions for which it was not designed. Design er- ror as a very common cause of failure may be speciﬁed by the fol- lowing items: used material, the size and shape of an engineering component and properties. A lot of numbers of different failure modes exist in all the ﬁelds of engineering, and they can be listed as: force induced elastic deformation, yielding, fatigue, fracture, corrosion, creep, buckling, thermal shock, etc. [3]. Creep, as one of possible failure modes was experimentally studied in these investigations. The phenomenon that arises in material in the 0261-3069/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.matdes.2012.12.037 ⇑ Corresponding author. Tel.: +385 51 651 491; fax: +385 51 651 490. E-mail address: brnic@riteh.hr (J. Brnic). Materials and Design 47 (2013) 497–504 Contents lists available at SciVerse ScienceDirect Materials and Design journal homepage: www.elsevier.com/locate/matdes