Vol.17, No.1, 2017, pp.61–73
UDC  669.15:539.431

BEHAVIOUR OF NIONIKRAL-70 IN LOW-CYCLE FATIGUE

Vujadin Aleksić1, Ljubica Milović2, Bojana Aleksić3, Srđan Bulatović4, Zijah Burzić5, Abubaker M. Hemer3

1)Materials Testing Institute, Belgrade, Serbia, vujadin.aleksic@institutims.rs

2)University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia

3)) University of Belgrade, Innovation Centre of the Faculty of Technology and Metallurgy, Belgrade, Serbia

4)Accreditation Body of Serbia (ATS), Belgrade, Serbia

5)Military-Technical Institute, Belgrade, Serbia

Abstract

Experimental research on the behaviour of high-strength low-alloy steel (HSLA) exposed to low-cycle fatigue (LCF) with controlled and fully reversible strain (Δε/2 = const, Rε = εmin/εmax = –1) has been analysed. LCF tests are performed on a series of smooth bar shaped specimens, 11 x 11 x 95 mm, parent metal (PM), welded joint (WJ) and simulated heat affected zone (SHAZ) of steel Nionikral 70 (NN-70) with semi-amplitude of controlled strain, Δε/2 = 0.40-0.80. The results of the experimental investigation have given us important information on the understanding of fatigue behaviour of steel NN-70 and its welded joints. In this work the results of static and dynamic-, that is monotonous and fatigue behaviour of the material, are compared, which is a practical contribution to the assessment of the behaviour of PM and WJ of steel NN-70 exposed to effects of low cycle fatigue, i.e. monotonous and fatigue behaviour of the material.

Keywords: high strength low-alloyed steel (HSLA), low-cycle fatigue (LCF), simulated heat affected zone (SHAZ), Nionikral 70 (NN-70)

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