| Course Unit Code | 636-3037/01 |
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| Number of ECTS Credits Allocated | 5 ECTS credits |
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| Type of Course Unit * | Compulsory |
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| Level of Course Unit * | Second Cycle |
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| Year of Study * | Second Year |
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| Semester when the Course Unit is delivered | Winter Semester |
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| Mode of Delivery | Face-to-face |
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| Language of Instruction | Czech |
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| Prerequisites and Co-Requisites | Course succeeds to compulsory courses of previous semester |
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| Name of Lecturer(s) | Personal ID | Name |
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| KUB014 | Dr. Ing. Zdeněk Kuboň |
| Summary |
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| The course is devoted to the most important technologies of joining materials for power engineering, especially their welding. The course includes brief theories of welding processes, weldability of materials including methods of its evaluation. Additionally, the treatment of materials prior to welding, the treatment after welding are included in the course (preheating of materials, including methods of preheating, controlled cooling after welding, post-welding heat treatment). Subsequently, the types and methods of welding are described, especially arc welding (manual arc welding, automatic or semi-automatic flux-core arc welding and its variants, use of protective gases, materials for electrodes, etc.). Attention is also focused on defects of welded joints, their definition and evaluation of admissibility, as well as methods of evaluation of welded joint quality in terms of occurrence of defects, respectively in terms of their structure and properties. Particular attention is paid to the welding of materials in power industry, where the properties of welded joints change during the high temperature exposure, and to the associated limitation of welding processes and combinations of different steels. |
| Learning Outcomes of the Course Unit |
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| Students will get acquainted with the main welding methods used in materials in power industry. They will know which factors influence decisively the weldability of materials; they will be able to choose the appropriate welding process for specific types of materials and their use. They will also be able to define suitable weldability tests as well as methods for checking the quality of the welded joints. They will control methods of characterization of the welded joints in terms of identification of possible degradation sites, especially in relation to creep damage. They will be able to analyze and evaluate existing technical solutions in the field of welding of materials for power engineering, especially in conventional power plants. |
| Course Contents |
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1. Introduction, theory of welding; basic concepts; the formation of the welded joint and its principal parts; deformation and internal stresses during welding process.
2. Weldability of metallic materials and its evaluation; weldability of steels, influence of individual elements on steel weldability.
3. Weldability evaluation – resistance to hot cracking, resistance to cold cracking, (incl. hydrogen embrittlement), resistance to lamellar tearing, resistance to annealing cracks.
4. Preheating, controlled cooling, post weld heat treatment - determination of preheating temperature, used methods, interpass temperature; controlled cooling; stress relief annealing, tempering after welding.
5. Types and methods of welding, fusion welding, pressure welding, friction welding, classification of methods, principal characteristics.
6. Arc welding: Electric arc, manual arc welding with coated electrode; principle, basic electrode characteristics, advantages and disadvantages of the process.
7. Arc welding: Submerged arc welding (APT), principle, additional materials for the APT method - wires and fluxes.
8. Methods of arc welding in a protective atmosphere: Gas metal arc welding (GMAW: MIG / MAG); Gas tungsten arc welding (TIG, WIG, GTAW); protective gases for individual methods, additional materials.
9. Defects of welded joints, their definition and admissibility assessment; Types of defects in the welded joints - cracks, cavities, non-metallic inclusions, cold joints / lack of fusion, defects in shape and dimensions; methods of defect evaluation in the welded joints.
10. Testing of welded joints: specific tests of welded joints - cross tensile tests (ČSN EN ISO 4136), longitudinal tensile tests of the weld metal (ČSN EN ISO 4178), bend tests (ČSN EN ISO 5173), impact tests (ČSN EN ISO 9016), fracture test (ČSN EN ISO 9017), tests of hardness (ČSN EN ISO 9015-1) and microhardness (ČSN EN ISO 9015-2)
11. Welding of materials for power industry - combination of steel grades, selection of welding consumables, influence of welding cycle on creep resistance of weld joints, strength factor of welded joint (SRF).
12. Structural analysis of welded joints - macrostructure, microstructure, or submicroscopic characteristics of welded joints; characterization of welded joints with respect to possible degradation sites, especially for creep degradation and corrosion, cracking of I-IV type in welded joints.
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| Recommended or Required Reading |
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| Required Reading: |
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CARY, H. B. and S. C. HELZER. Modern welding technology. 6th ed., Upper Saddle River: Pearson Prentice Hall, 2005. ISBN 0-13-113029-3.
JEFFUS, L. F. Welding: principles and applications. 8th ed. Boston: Cengage Learning, 2016. ISBN 978-1-305-49469-5.
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KUBOŇ, Z. Technologie spojování materiálů pro energetiku. Ostrava: VŠB–TU Ostrava, 2019.
MINAŘÍK, V. Obloukové svařování. 2. aktualiz. vyd., Praha: Scientia, 2003. ISBN 80-7183-285-5.
CARY, H. B. and S. C. HELZER. Modern welding technology. 6th ed., Upper Saddle River: Pearson Prentice Hall, 2005. ISBN 0-13-113029-3.
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| Recommended Reading: |
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KOÇAK, Mustafa, ed. Proceedings of the International Congress on Advances in Welding Science & Technology for Construction, Energy & Transportation Systems (AWST-2011), 24-25 October, 2011, at Gloria Hotels & Resorts, Antalya, Turkey. Istanbul: Ben Yazarim Yayinlari, 2011. ISBN 978-605-4424-23-8.
LIPPOLD, John. C. Welding Metallurgy and Weldability. Hoboken [NJ]: John Wiley & Sons, 2015, 400 s. ISBN 978-1-118-23070-1. |
JANALÍKOVÁ, Eva, Ed. Nekonvenční metody svařování: studijní materiály. Část I, Svařování kovů : Ostrava: Český svářečský ústav, 2013. ISBN 978-80-248-2887-9.
AMBROŽ, O., B. KANDUS a J. KUBÍČEK. Technologie svařování a zařízení: učební texty pro kurzy svářečských inženýrů a technologů. Ostrava: Zeross, 2001. ISBN 80-85771-81-0.
KOUKAL, J., D. SCHWARZ a J. HAJDÍK. Materiály a jejich svařitelnost: učební texty pro kurzy mezinárodních svářečských inženýrů, technologů a pro výuku svařování na vysokých školách. Ostrava: Český svářečský ústav, 2009. ISBN 978-80-248-2025-5.
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| Planned learning activities and teaching methods |
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| Lectures, Seminars, Tutorials, Experimental work in labs, Project work |
| Assesment methods and criteria |
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| Task Title | Task Type | Maximum Number of Points
(Act. for Subtasks) | Minimum Number of Points for Task Passing |
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| Credit and Examination | Credit and Examination | 100 (100) | 51 |
| Credit | Credit | 35 | 21 |
| Examination | Examination | 65 | 30 |