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Steels for the automotive industry
Boček, Jan ; Mauder, Tomáš (referee) ; Štětina, Josef (advisor)
The subject of this thesis is research of usage of modern steel in the automotive industry. Because car bodies are subjected to strict requirements, multiple steel grades are used in their construction. Steel provides suitable properties such as good weldability, formability, and high strength. It has its disadvantages as well, and because of that, other materials has started to be used. This thesis contains a general overview about steel, the theory of usage of steel in the automotive industry and information about specific steels used and their properties. Particularly they are HSLA steels, low carbon steels, dual phase steels and TRIP steels. Nowadays in the automotive industry, steels are the main material used and it isn’t unreasonable to think that it will stay that way in the future.
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Study of weld plasticity of deep-drawn sheets welded by Laser-TIG technology
Kutil, Petr ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
This thesis is focused on laser welding and hybrid laser-TIG welding. The first part contains a brief theoretical description of these technologies. Standard quality and plasticity tests of welded joint are also mentioned. The second, experimental part, centres on the study of plasticity of tailored blanks (made of different types of HSLA steel), that are welded with laser and laser-TIG technology. The aim of the thesis is to assess process parameters effect on weld suitability for following deep drawning operation. Based on the calculated and measured figures obtained from the experiment, the most suitable welding parameters were chosen.
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Use of the Laser-TIG hybrid method in the automotive industry
Mrňa, Libor ; Šebestová, Hana ; Horník, Petr ; Antes, J. ; Kutil, P. ; Křápek, L. ; Iván, L.
High demands are placed on the joining of body parts in terms of strength and consistent quality. Simultaneously, production time minimizing is required. In addition to the most common spot resistance welding, laser welding is often used. This provides high welding speed as well as good strength. Of course, there is a general desire to increase the overall strength of the body-in-white while reducing production costs, which are conflicting requirements. The only way forward is to use modern steel materials (HSLA steels, DP steels, etc.) and to use new, more advanced joining technologies. The paper presents possibilities of hybrid Laser-TIG welding technology.
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Steels for the automotive industry
Boček, Jan ; Mauder, Tomáš (referee) ; Štětina, Josef (advisor)
The subject of this thesis is research of usage of modern steel in the automotive industry. Because car bodies are subjected to strict requirements, multiple steel grades are used in their construction. Steel provides suitable properties such as good weldability, formability, and high strength. It has its disadvantages as well, and because of that, other materials has started to be used. This thesis contains a general overview about steel, the theory of usage of steel in the automotive industry and information about specific steels used and their properties. Particularly they are HSLA steels, low carbon steels, dual phase steels and TRIP steels. Nowadays in the automotive industry, steels are the main material used and it isn’t unreasonable to think that it will stay that way in the future.
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Study of weld plasticity of deep-drawn sheets welded by Laser-TIG technology
Kutil, Petr ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
This thesis is focused on laser welding and hybrid laser-TIG welding. The first part contains a brief theoretical description of these technologies. Standard quality and plasticity tests of welded joint are also mentioned. The second, experimental part, centres on the study of plasticity of tailored blanks (made of different types of HSLA steel), that are welded with laser and laser-TIG technology. The aim of the thesis is to assess process parameters effect on weld suitability for following deep drawning operation. Based on the calculated and measured figures obtained from the experiment, the most suitable welding parameters were chosen.
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Synergic effects of laser – TIG welding
Kubíček, J. ; Doležal, P. ; Mrňa, Libor ; Šebestová, Hana ; Horník, Petr
Laser welding compared to conventional arc methods is accompanied by rapid cooling rates. It can lead to the formation of undesirable microstructure of the weld metal and heat affected zone of some steel grades which has a negative impact on their mechanical properties. The preheating is quite problematic because of high speed of laser welding. The possibility of preheating by the heat of the arc discharge of the associated TIG burner has been tested. Precise holder has been fabricated to fix the burner to the laser welding head allowing TIG electrode positioning towards the laser beam and the workpiece. A number of high strength steel S460MC and S700MC welding experiments was performed. The effect of TIG current on microstructural changes has been proven. Some welding experiments were compared to the SYSWELD welding simulations.\n
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Utilization of the HSLA toolbox for the FPGA prototyping
Pohl, Zdeněk ; Líčko, M.
An innovative design-flow for DSP algorithms usign high-speed logarithmic arithmetic (HSLA) toolbox is introduced on a demo RLS lattice application. Utilization of toolbox provides effective design time shortening and it makes designer work easier. Firstly, scripts in Matlab are written and checked. From working scripts, design is decomposed in Simulink to cycle-exact simulation and rewritten in Celoxica DK1 tool. Finally, hardware is targeted from DK1 and results are compared with simulations.
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Extension for Xilinx System Generator - logarithmic arithmetic blockset
Líčko, Miroslav ; Métais, B. ; Tichý, Milan ; Matoušek, Rudolf
The paper introduces support of floating point(FP) data format for the Xilinx System Generator (XSG) using logarithmic arithmetic. This type of arithmetic seems to be one of the promising ways to solve FP sort of DSP problems in practice. Our 32-bit high-speed logarithmic arithmetic (HSLA) keeps the accuracy according to IEEE 754 and speed up some kinds of FP algorithms. Promising is 19-bit equivalent utilised int this paper. It offers reasonable precision for the practical use and has min.HW requirements.
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