Deliverables Dependence of structure and mechanical properties on heat treatment regime Dependence of structure and mechanical properties on heat treatment regime by finally composition: The finally tests were made with the new reference iron alloyed with about 0,4 % vanadium and 1,0% nickel and treated with alloy Remag (1,45 %) from Elkem. (finally composition) Three different regimes of heat treatment were used: - 1050°C for 16 hrs; 640°C for 12 hrs, followed by air-cooling. - 1050°C for 12 hrs; 640°C for 8 hrs, followed by air-cooling. - 1100°C for 16 hrs; 700°C for 30 min, followed by air-cooling. After the third regime of heat treatment the structure consists only of ferrite and the mechanical properties were better as the other one. Determination of the quality guideline: The quality guideline was developed in result of conducted tests and constituted the base pouring the reference casting. On the quality guideline are the determination of the target values (chemical composition, mechanical properties) and the quality check of used raw materials (for instance: foundry pig iron, treatment agent, inoculant) very important. Determination of the heat treatment guideline: The heat treatment guideline was developed in result of conducted heat treatments with the finally alloy and constituted the base heat treatment regime of practice castings. The heat treatment regime is determined 1100°C for 16 hours and 700°C for 30 min followed by air-cooling. It will be used two inert gas-muffle furnaces. Checking the mechanical properties of a reference casting on heat treatment regime: A reference casting was selected on the range of products from Flender Guss. Concurrently to the casting was a Y-test unit poured checking the mechanical properties with the determined heat treatment regime.The yield stress arrived about 450 to 470N/mm² and the tensile strength ca. 600N/mm². The elongation constituted about 12,5% to 14%. Improved knowledge of ductile iron Improved knowledge regarding micro-alloying of ductile iron: Ductile iron has traditionally been classified and standardised according to its strength and ductility. In general the different strength and ductility levels has been achieved by alloying to control the ferrite/pearlite balance in the iron. Alloying has mainly been based on elements that alter the transformation behaviour in the material, typically due to retarding the diffusibility of carbon in the matrix. In addition large amount of work has been done to increase the number of graphite nodules per unit volume and to control the size and shape of the graphite nodules. In the later years very high strength ductile irons have been produced after a long and very expensive heat treatment. The current project aims at establishing micro-alloying as an alternate route to strength enhancement in ductile iron. The main advantages include significant strength enhancement in the as-cast condition, with no or very little heat treatment, by utilising micro-alloying. Initial results have shown that micro-alloying of ductile iron provides an iron with increased as-cast mechanical performance. Yield strength of higher than 520MPa has been achieved in as-cast ferritic ductile iron. Models to explain the underlying mechanisms are being developed to provide tools to control the microstructure evolution and the resulting mechanical properties. FEM-based mathematical model that can accurately predict microstructure and mechanical properties in ductile iron: A FEM-based software code is being developed to accurately predict the microstructure evolution in micro-alloyed ductile cast iron. The applied microstructure model draws together established knowledge of thermodynamic and kinetic theory with experimental data to describe the microstructure evolution during casting. The microstructure predictions are connected to mechanical property predictions using empirical equations that take into account the chemical composition, volume fraction of the different microstructural components and the actual cooling rate. Software tool that permits to evaluate the effect of the manufacturing process on the real mechanical behaviour The main objective of the DILIGHT research project was to develop a new generation of low cost high performance ductile cast iron for lightweight design of automotive components. In the framework of this project, the CRF has produced the following results. - Economical evaluation: In order to carry out a detailed cost analysis, the whole production chain has been considered and a software platform has been developed by CRF. In such a way it is possible to consider the effects of the modifications implemented in the process design phase (casting system geometry and process parameters) not only as far as the casting phase itself is concerned, but also all the other centres that allow the product manufacturing. Moreover, this methodology permitted not only to quantify the entire sand casting manufacturing cost, but also even to accurately monitor each constituent cost item. Indeed, the whole computed cost has been split into single components in terms of material, energy, labour, equipments, premises, maintenance, consumables and machinery set-up. It is worth noting that the performed cost analysis, and therefore the following considerations, have been based on a particular chosen manufacturing process, characterized, for instance, by a certain distribution of the depreciations and maintenance costs and by real production capacities and business volumes. - Software tool that permits to evaluate the effect of the manufacturing process on the real mechanical behaviour: In order to transfer the information deriving from the simulation to the microstructure modelling, it was developed a dedicated software tool. The considered step are: remeshing, displacement transfer, stresses transfer, input file compilation. Furthermore, this methodology permit to evaluate the effect of the manufacturing process on the real mechanical behaviour of the component. The obtained results clearly demonstrate the influence of the preexistent stresses. New production process The major output of the DILIGHT project is a new family of high strength ductile cast iron for light weight application, new micro alloyed foundry ferroalloys, prototypes of automobile crankshaft components and power transmission gears, life cycle assessment incorporating environmental issues and mathematical process models developed to predict the properties of new cast irons. New production processes are envisaged to have a technology to produce the new material under industrial conditions. It should be possible to include this technology in the foundry process and combine it with our other products (return scrap problem and separation). It is also important to have a sure process for inoculation and MG-treatment with the micro alloys and without annealing. Life cycle assessment The DILIGHT project intends to generate a Life Cycle Assessment (LCA) that compares the environmental impacts of alternative materials/processes for the production of automotive and selected engineering components. Specifically, the project will compare the environmental impacts of conventional cast iron and aluminium alloy components with those to be made using the DILIGHT alloy. The anticipated output is an unequivocal statement of the environmental benefit of the DILIGHT alloy. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
