Grey cast iron belongs to materials for casting production, which have wide application for different industry branches. Wide spectrum of properties of these materials is given by the structure of base metal matrix, which can be influenced with heat treatment. Processes of annealing can be applied for grey cast iron without problems. During heat treatment processes, where higher cooling rates are used, the thermal and structural strains become important. Usage and conditions of such heat treatment for grey cast iron castings of common production are the subject of evaluation of this article.

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Ductile cast iron (GS) has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.Keywords: graphitization, shrinkage, metalurgical quality, furan molding sands W ostatnich latach obserwuje się intensywny wzrost produkcji odlewów z żeliwa sferoidalnego. Dotyczy to także zastępo-wania tym tworzywem odlewów staliwnych. W przypadku masywnych odlewów szczególnie duże znaczenie odgrywa przebieg skurczu tworzywa. Powstawanie skurczu wiąże się z materiałem odlewu, jego konstrukcją, układem wlewowym oraz materiałem formy. Celem badań zaprezentowanych w artykule jest ocena wpływu właściwości technologicznych formy na podstawie skurczu. Odlano 12 kształtek w 3 formach, aby ocenić wpływ jakości formy na skurcz odlewów z żeliwa sferoidalnego.

Recently, the castings made from aluminum-silicon alloys by pressure die casting are increasingly used in the automotive industry. In practice, on these castings are high demands, mainly demands on quality of their structure, operating life and safety ensuring of their utilization. The AlSi5Cu3 alloy castings are widely used for production of car components. After the prescribed tests, the cracks and low mechanical properties have been identified for several castings of this alloy, which were produced by low pressure casting into a metal mould and subsequent they were heat treated. Therefore, analyses of the castings were realized to determine the causes of these defects. Evaluation of structure of the AlSi5Cu3 alloy and causes of failure were the subjects of investigation presented in this article.Keywords: AlSi5Cu3 alloy, microstructure, cracks, hardnessZastosowanie odlewów ciśnieniowych ze stopów Al-Si ustawicznie wzrasta w przemyśle samochodowym, gdzie stopy te muszą spełniać wysokie wymagania odnośnie do jakości ich struktury, żywotności i bezpiecznego użytkowania. Odlewy ze stopu AlSi5Cu3 są szeroko stosowane w produkcji części samochodów. Wg pracy wady pęknięć wewnętrznych i niskie właściwości mechaniczne posiada część odlewów obrabianych cieplnie, odlanych do form metalowych pod niskim ciśnieniem. Praca poświęcona jest ocenie struktury i przyczynom pękania odlewów ze stopu AlSi5Cu3.

With increasing tendency of die castings production, also the possibility to produce castings with maximum usage of molten metal grows. Residual of non-used molten metal, e.g. sprues, feeders, splashes and saw-dusts are used in next production as returning material. With returning material a lot of non-suitable elements is brought into the melting process, but with decreasing of input costs it creates inseparable part of production process. Usage of returning material in melt production has negative influence on final quality of produced castings, because of bringing of inheritable properties into produced melt. Important factor in melt production with the amount of returning material is to know to set its optimal amount and the way of melt treatment to achieve the same results in casting quality in comparison to the casting production from clean materials.