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Vol.8, No3, 2008,
pp. 149-158 |
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FRACTURE AND FATIGUE BEHAVIOUR OF NIOMOL 490K WELDED JOINT Mersida Manjgo 1 Aleksandar Sedmak, Biljana Grujić 2 1 Faculty of Mechanical Engineering, University of Mostar, Bosnia and Herzegovina 2 Innovation Centre of the Faculty of Mechanical Engineering, University of Belgrade |
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Abstract The aim of this paper is testing specimens for analysing crack behaviour in welded joints of pressure vessels, made of microalloyed steel, by applying fracture mechanics parameters. Steel NIOMOL 490 K is designed for welded structures exposed to dynamic loads and low temperature, and in respect to this, apart to sufficient strength, it must also have acceptable toughness. In the course of understanding causes and modes of crack initiation and growth in welded joints of high strength steels, it is necessary to establish how the heterogeneity of microstructure and mechanical properties, primarily in HAZ, affect crack initiation and growth, as well as fatigue crack growth parameters. This paper should contribute to the development of basic parameters and criteria for the acceptance of crack-like defects in pressure vessels aimed to operate at conditions of low temperature and aggressive environment. Keywords: welded joint, high strength steel, crack growth rate, fatigue threshold, structural integrity |
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full article (485 kB)
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