In electroslag remelting (ESR), the material cast into electrodes is successively melted in a slag bath, refined by various chemical and physical mechanisms and solidified in a water-cooled copper mould. In addition to a significantly improved degree of purity, controlled solidification can also be achieved. Compared to ingot casting, the low melt volume and the induced stirring result in a reduction of macrosegregation and, due to the low local solidification rates, a reduction of microsegregation. At the contact surface between the slag and the mould, a slag skin about 1-3 mm thick is formed, which on the one hand reduces the direct heat loss to the mould, but on the other hand also reduces the cooling speed of the metal.
The aim of the project is to break new ground in order to enable the hot-dip coating of high-alloy steels. This goal is to be achieved by modifying the pre-treatment in combination with altered alloy compositions in the zinc bath. Due to the large number of chemical changes, it is essential to characterize the reactions taking place and the structure of the layer composite with the aid of electron microscopic examinations.
The aim of this research work is to further develop the electrochemically deposited SnZn system by adding a passive layer-forming element. This ternary alloy system should have better corrosion resistance due to an improved, insoluble oxide barrier layer, without worsening the property profile of the already introduced Sn-Zn layer. This barrier layer is to be protected by an element of the 4th period.
The aim of the project is the development of a new process for the separation of hard zinc and zinc ash from the zinc bath by means of centrifugal technology in a continuous galvanizing process. A pilot plant will be docked to a production furnace and the technical feasibility will be tested in a medium-sized galvanizing company. Based on this, a recycling concept for the modified composition of the galvanizing residue is developed.
The thixoforming of metals is still a young production process, located between the primary forming and forming. Today, various components are already manufactured in series according to this manufacturing principle, mainly by thixocasting and thioxomoulding, almost exclusively using aluminium and magnesium. The processing of steels and other process routes are still under development. Even after these selective advances and despite a number of international research activities, it must be stated that this area of production has not been sufficiently researched either in its fundamentals or in its application by the various process variants and for many metals. There are numerous reasons for further scientific implementation of thixoforming. On the one hand, it is the great potential opened up by the semi-liquid state in terms of shaping and properties.
IME Process Metallurgy and Metal Recycling
Chair of the RWTH University
Address:
Intzestr. 3
52056 Aachen
Gebäude 1401
Phone: +49 241 80 95851
Email: institut@ime-aachen.de
URL: www.metallurgie.rwth-aachen.de


