Fraunhofer Institute for Large Structures in Production Engineering IGP
© Fraunhofer IGP Rostock
Thermal Joining Engineering
Work area
Thermal cutting, coating and joining processes play a central role as value-added and quality determining manufacturing steps in a large number of production processes. In highly industrialised branches, welded joints and welding processes, in particular, have to satisfy constantly growing and changing demands with respect to cost-effectiveness, flexibility and quality.
These include, for example, high-quality processing of modern materials with often high demands on the mechanical and technological properties with consistent process reliability, the assurance of the part integrity of welded components of innovative lightweight steel constructions subject to high static and cyclic loads, increases in the cost-effectiveness of welding processes through modern automation solutions, and the introduction of highly productive welding methods to increase competitiveness as an answer to the growing pressure of costs in globalised markets.
In order to find long-term and sustainable solutions to the resulting technological and economic challenges, the Thermal Joining Engineering group at Fraunhofer IGP is continuously engaged in innovative research and development on current and future issues in the fields of shipbuilding, structural steel work, onshore and offshore wind energy. We always strive to holistically evaluate technological, metallurgical and design aspects of the respective welding applications within the value-added chain.
In 2020 the group changed its name. Welding Engineering has become Thermal Joining Engineering. Group Head Dr -Ing Andreas Gericke explains: „The change of name was necessary to communicate and represent our core area of welding technology as well as our other skills in the area of soldering and thermal spraying, which have grown sustainably and successfully over the years. In this way, we aim to be more visible to potential customers and continue strategic growth in these areas”.
Project overview
Welding under Water
Compensate for risks associated with wet welding under water
Induction heating engineering to improve the weld seam qualitiy for subsea welding of finegrain steels
The research project investigates the application of induction technology for pre- and post-heating in manual wet arc welding. Due to the influence of the media, there are high levels of hydrogen input and, due to the strong convection, high cooling rates after welding. As a result, critical material properties and cracks can result. The effective introduction of energy by means of induction is intended to be used for the practical compensation of subsea-specific risks during wet welding and consequently, also enabling the safe joining of high-strength steels. This is necessary for the economical and high-quality repair of structures in hydraulic steel engineering. Application guidelines for the use of induction heating engineering are in development.
Electroslag channel welding
Electroslag channel welding becomes plant-compatible
Development of a mobile electroslag (ES) channel welding system for construction site applications
The welding processing of thick-walled sheets is necessary for many constructions in the maritime sector in constrained positions and under construction site conditions. ES duct welding is a welding process for single- layer welding of vertical seam connections which is particularly economical and with low distortion. However, the inadequate level of knowledge about welding metallurgy and the lack of system technology mean that it is rarely used. The aim is therefore to develop a mobile ES duct welding system for use on butt and T-joints, as well as to adapt the system technology, welding engineering and welding metallurgy of ES duct welding to European manufacturing specifications.
Arc Brazing
Arc brazing as a substitute for welding in steel construction?
Use of arc brazing to join components on steel structures subject to high vibration levels
In steel construction, it is necessary to weld attachments without a primary load bearing function to structures subject to vibrational stress, which has an influence on the service life and design of high-strength steels. The project investigated whether arc brazing with copper-based solders is suitable for the substitution of welding processes in steel construction. The investigations show that the use of arc brazing to join attachments can extend the service life of the entire construction by up to 500% without the need for post-weld treatment. For example, there is a saving of 50 tonnes in weight on a tubular steel tower for wind turbines without reducing the static load-bearing capacity of the payload parts.
Project overview
Projects
Services
- Application-oriented development and optimisation of thermal joining, cutting and coating processes
- Determination of mechanical-technological and fracture-mechanical material, joint and component properties
- Analysis of welding processes by combined optical, electrical and thermal measuring methods
- Development and qualification of economical methods for improving the fatigue strength of welded structures
- Development and qualification of welding and soldering additives as well as thermal sprayed coatings
- Chemical analyses (spark emission spectrometry, carrier gas extraction to determine O, N, H content in various metals, energy dispersive X-ray spectroscopy EDX)
- Structural analysis and feature determination of Fe, Cu, Al and Ni-based materials by means of light and scanning electron microscopy (SEM)
- Determination of welding-related distortion as well as of residual stress states and development of countermeasures
- Automation of welding processes and development of monitoring systems
- External and construction supervision with mobile measuring and analysis technology
- Design and dimensioning of welded and soldered joints
- Welding technology, metallurgical and construction consultancy
- Development testing and inspection of subsea connection technologies
Equipment
Welding laboratory
- Submerged arc tandem double wire welding machine
- Electro gas welding machine
- Robot gantry with adaptive welding and cutting device
- Submerged arc manual welder
- various MSG, plasma, TIG, autogenous welding and cutting equipment
- Heat treatment furnaces
- autogenous preheating system
- div. measuring equipment
- induction heat technology
- various stud welding equipment
Analytical laboratory - OES device
- grinding and polishing machines
- Hot embedding press
- reflected and transmitted light microscopes
- Ultrasonic testing device
- ONH analyzer
- Hydrogen analyzer
- Hardness tester
- ESPI residual stress tester