345-0502/05 – Theory of Welding (TS)
Gurantor department | Department of Mechanical Technology | Credits | 6 |
Subject guarantor | prof. Ing. Petr Mohyla, Ph.D. | Subject version guarantor | prof. Ing. Petr Mohyla, Ph.D. |
Study level | undergraduate or graduate | Requirement | Compulsory |
Year | 1 | Semester | summer |
| | Study language | English |
Year of introduction | 2020/2021 | Year of cancellation | |
Intended for the faculties | FS | Intended for study types | Follow-up Master |
Subject aims expressed by acquired skills and competences
The aim of the object is to provide students with the complex professional information about the theoretical principles of welded joints formation at fusion and pressure welding, physical principles of the metal welding processes, metallurgical behavior between weld metal and slag or shielding gases, weld metal formation and weld metal crystallization principles, phase transformations in the weld joints, weld joints cracking phenomena, deformation and tension processes in the welds, materials weldability and theoretical principles of materials brazing. Based on the received information the students will be able to independently professionaly solve the task in the technical activities in the field of welding.
Teaching methods
Lectures
Individual consultations
Tutorials
Experimental work in labs
Summary
Basic subject for Master's degree, focused on welding. Students become acquainted with the principle of the welded joint creation during fusion and solid-state welding and with the importance of thermal cycles and their influence on the structure and properties of welded joints. The course contains basic principles of cracks creation in welded joints and theoretical knowledge about the weldability of different types of materials. Subject included also theoretical background of soldering and brazing. Students will also be informed about welding of heterogeneous materials, welding of cast irons and cast steels, non-ferrous metals and plastics.
Compulsory literature:
BECKERT, M.: Grundlagen der Schweisstechnik, VT Berlin, 1977.
EASTERLING, K.: Introduction to the Physical Metallurgy of Welding, BMM,
London, 1983.
Recommended literature:
EASTERLING, K.: Introduction to the Physical Metallurgy of Welding, BMM, London, 1983.
Additional study materials
Way of continuous check of knowledge in the course of semester
Projects, test.
E-learning
Other requirements
Active participation in seminars min. 80%.
Prerequisities
Subject has no prerequisities.
Co-requisities
Subject has no co-requisities.
Subject syllabus:
Lectures:
1. Theory of welded joint creation during fusion welding and solid-state welding. Energy sources used for welding. Weld thermal cycles. Measurement of thermal cycles, calculation of thermal cycles.
2. Theory of heat-affected zone of welded joints. Effect of thermal cycle on HAZ. Precipitation and degradation processes in HAZ.
3. Solidification of the weld metal. Segregation and liquation. External shape factor of weld. Structure and properties of weld metal.
4. Metallurgical processes in weld metal. Theory of slag. Alloying of weld metal.
5. Desulfurization and dephosphorization of the weld metal. Absorption of oxygen in weld metal, desoxidation. Absorption of hydrogen in weld metal. Absorption of nitrogen in weld metal.
6. Cracks in welded joints. Causes of occurrence, susceptibility criteria, cracking tests. Cold cracking, hot cracking, lamellar, annealing , underclad and corrosion cracking.
7. The theory of stress and deformation in welded joints. Calculations. Temporary and residual stresses. Methods of reducing of stress and deformation in welded joints.
8. The theory of soldering. Defects of solder joints. Properties of solder joints. Solderability tests. Solders and fluxes.
9. Welding of heterogeneous joints. Effect of chemical composition and welding methods. Using Schaffler diagram. Problems in welding of heterogeneous joints.
10. Weldability of heat resistant steels
11. Weldability of stainless steels. Weldability of cast irons and cast steels.
12. Weldability of copper and its alloys. Weldability of aluminum and its alloys.
13. Weldability of titanium and its alloys. Weldability of nickel and its alloys.
14. Welding of plastics.
Excercises:
1. Introductory exercises. Learning outcomes and competences. Safety training. Repetition of the welding basics.
2. Thermal and deformation cycle of welding, methods of calculation and measurement of temperature cycles. Project No. 1 - Calculation of temperature cycles.
3. Numerical solution of welding temperature fields.
4. Laboratory Exercise - Measurement and Temperature Control of Welding and Heat Treatment. Measurement of temperature cycles in arc welding.
5. Consultation on Project No.1. Analytical and numerical solution of temperature fields.
6. Laboratory exercise: metallographic evaluation of HAZ for selected welding technologies.
7. Entering of project No. 2 - Welding of heterogeneous weld joint.
8. Technologies and techniques of heterogeneous welding joints, welding of non-ferrous metals. Using a virtual welding simulator.
9. Consultation on project No.2. Material Weldability Rating.
10. Laboratory exercise: residual stress measurement, welding deformation, material separation, flame straightening techniques.
11. Welding of plastics, soldering and bonding.
12. Project No. 3 - Determination of weld joints deformations.
13. Excursion to the engineering company.
14. Final Exercise. Test. Evaluation of projects.
Conditions for subject completion
Occurrence in study plans
Occurrence in special blocks
Assessment of instruction