General to the project:
As the title indicates, the focus is laid on joining of metallic materials. In more detail projects are divided into two areas concentrating on ‘materials’ and ‘processes’ and additionally into seven projects with direct company contributions. Each area additionally owns one strategic project of general interest. Generally all projects have more or less pronounced relations. These existing thematic links are strengthened by means of annual partner days of the project group. These exchanges are very fruitful in deepening the understanding and applying of special solution to other problems.
Project 1.1 Advanced welding technologies for Molybdenum and its alloys (MOLY)
Demand for highly innovative manufacturing processes in modern industry is rising and welding technologies as important production skills are a suitable approach to meet these needs. Molybdenum and its alloys are widely used materials due to their attractive high temperature properties. Powder metallurgical (PM) processed Molybdenum (Mo) alloys show decisive advantages in a variety of high integrity applications e.g. lighting, medical, thermal processing, electronics, etc.
Project 1.2 Influence of micro-alloying elements on strength and ductility of ultra-high strength welds
The need of constructions with reduced weight and the requirement of carrying higher loads increase the demands on high strength steels. Developing high strength filler materials with acceptable toughness is an essential task for the realisation of these ultra-high strength steel designs. The development of filler metals has reached now its limitation at a yield strength of 960 MPa. The goal in the framework of this project is the development of a filler material with a yield strength of 1100 MPa and an adequate toughness. An important task is to test this behaviour in joints and to ensure a safe and reliable processing of these ultra-high strength steels.
Increasing the strength by rising the C-, Ni-, Mn- or Cr-content leads to an insufficient balance of strength and toughness. Alloying small amounts of e.g. B, Ti or Zr up to a few hundreds of ppm can be considered as an alternative concept compared to the conventional solid solution hardening. These micro-alloying elements can influence grain growth behaviour during
solidification and cooling. Furthermore they can act as precipitates which result in a strengthening effect. Also the role of inclusions in combination with micro-alloying elements
has to be considered. In order to reduce the experimental effort, thermodynamic and kinetic simulations will be performed to understand and learn about the effect of the different alloying elements. Finally the knowledge of structure-properties-relationship and the influence of micro-alloying elements
should allow a precise alloy development of filler metals.
Project 1.3 Impact of innovative welding technologies on ultra high strength steel welds
Project 2.2 High performace welding of rails
Project 2.3 Linear Friction Welding of Chains
S1: Microstructure and mechanical behaviour of electron beam welded joints of 9-12% Cr steel (EBW)