1. Application of semantic technology for calculation of welding time in the development of new productsAmbrož Stropnik, Tomaž Vuherer, Ivan Samardžić, Milan Zorman, 2017, original scientific article Abstract: Determining the time of execution is very important in the early stages of each project (e.g. making offers, design phase etc.), especially in the stage of planning. This paper presents our approach to estimating the welding time for the purposes of planning the manufacturing processes. The approach is based on the knowledge of welding experts from the Nieros metal d.o.o. company and standards of welding (international and internal). An expert system was developed based on semantic web technologies for calculating the welding time in the product design phase and it is strongly integrated with the main ERP system of the Nieros metal d.o.o. company. Test results are presented at the end of this article. Keywords: expert systems, new product development, ontology, welding of steels Published in DKUM: 23.08.2017; Views: 885; Downloads: 376
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2. Weldability prediction of high strength steel S960QL after weld thermal cycle simulationMarko Dunđer, Tomaž Vuherer, Ivan Samardžić, 2014, original scientific article Abstract: This paper presents weld thermal cycle simulation of high strength steel S960QL, and describes influence of cooling time t8/5 on hardness and impact toughness of weld thermal cycle simulated specimens. Furthermore, it presents analysis of characteristic fractions done by electron scanning microscope which can contribute to determination of welding parameters for S960QL steel. Keywords: high strength steels, S960QL steel, weldability, weld thermal cycle simulation, hardness, toughness Published in DKUM: 03.07.2017; Views: 2604; Downloads: 138
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3. Weldability of microalloyed high strength steels TStE 420 and S960QLMarko Dunđer, Tomaž Vuherer, Ivan Samardžić, 2014, original scientific article Abstract: The paper presents research of weldability of microalloyed high strength steels TStE 420 and S960QL after weld thermal cycle simulation. Beside mechanical properties hardness and impact strength, the microstructures of characteristic weld thermal cycled structures for both steels are given. The results will contribure to determination of weakest points in Heat Affected Zone of both steels. Keywords: weldabilty, high strength steels, mechanical properties, TStE 420, S960QL Published in DKUM: 03.07.2017; Views: 2027; Downloads: 125
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5. Suitability of heat treatment for crack resistance of material in the connection part of heavy transporter for liquid slagTomaž Vuherer, Ljubica Milović, Milorad Zrilić, Ivan Samardžić, Vladimir Gliha, 2013, short scientific article Abstract: The post weld heat treatment (PWHT) was used to reduce the level of the residual stresses and increase of the crack resistance of the materal in the cnnection part. The article presents the results of the residual stress measurements immediately after welding and after the stress relaxation by the PWHT. Keywords: weld, heat treatment, residual stress, stress relaxation, crack resistance Published in DKUM: 03.07.2017; Views: 1970; Downloads: 92
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6. Influence of vibrations on residual stresses distribution in welded jointsIvan Samardžić, Tomaž Vuherer, Dejan Marić, Pejo Konjatić, 2015, original scientific article Abstract: This paper presents research experience related to implementation of vibrations on residual stress relief with the equipment for treatment by vibration method. The paper provides explanation of effects achieved by vibration method when implemented during welding, and elaborates advantages and disadvantages of that method applied after welding process. In order to present effects of vibration on solid structures, there was experimental analysis performed and compared with heat treatment. Keywords: welding, vibrations, residual stress, heat treatment Published in DKUM: 03.07.2017; Views: 881; Downloads: 115
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8. Fatigue crack growth and fracture mechanics analysis of a working roll surface layer materialMatej Drobne, Tomaž Vuherer, Ivan Samardžić, Srečko Glodež, 2014, original scientific article Abstract: Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material is presented in this paper. The research is done on a hot strip mill working roll where High Chromium Steel is used for roll’s shell material. To obtain corresponding parameters, a rectangular single edge notched bend specimens – SENB, according to standard BS 7448, were used. The fatigue crack growth analysis was done on a resonant testing machine with use of special crack gauges, while for fracture mechanics parameters the electro–mechanical testing machine was used. Keywords: fracture mechanics, fatigue crack growth, metal forming, rolling process, high chromium steel Published in DKUM: 03.07.2017; Views: 879; Downloads: 114
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10. Microstructural investigation of the heat-affected zone of simulated welded joint of P91 steelTomaž Vuherer, Marko Dunđer, Ljubica Milović, Milorad Zrilić, Ivan Samardžić, 2013, original scientific article Abstract: In the process of testing real components exposed to elevated temperature, it is not possible to neglect cracks. The most significant cracks can be induced by welding, which is applied for joining of structural components. Pressure equipment in service is also exposed to high pressure and high stresses. Materials for their manufacturing are designed to resist high stressat elevated temperature, and to meet requirements regarding creep resistance. The objective of this study is to investigate microstructure of different regions of the heat affected zone in T/P91 steels by using thermal simulation instead of welding. Keywords: welded joints, microstructures, P91 steel, heat-affected zone, heat treatment Published in DKUM: 10.07.2015; Views: 988; Downloads: 158
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