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1

Influence of Process Parameters on Ceroxide Formation in Low-Carbon Steels

Vaucheret A., Nicolini C., Carton J.-F., Jacquet P.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 4

90--96

EN

Ceroxides are surface defects caused by a mold-metal reaction during the casting process of steels. This type of defect may affect a large area, but it is located only on the skin of the parts. It does not affect the core of the parts nor its mechanical properties. Nevertheless, ceroxides induce a lack of material on the surface, forming a kind of crater and needing complementary surfacing. The defect is also composed by several non-metallic inclusions containing Al, Mg, Si and O. An EDX analysis by mapping show these elements involved in the mold-metal reaction. The presence of these oxides could confirm the hypothesis of the deoxidizer reoxidation found in the bibliography. To better understand the specific conditions of ceroxide formation, the first step was to find of way to generate systematically this defect at each casting. Two patterns with different filling rate were designed, simulated on Quikcast and tested. The pattern with turbulent filling rate allowed the formation of ceroxide at each casting and so was used during this study. This result shows that the filling rate of the mold could be considered as a first order parameter in ceroxide formation. Then, a specific experimental set up was designed to characterize this defect. The analysis of the defect was done for sizing it: surface and depth. Finally, some key parameters on defect formation were determined like the nature of deoxidizer or the amount of oxygen in the mould. Some laboratory tests were lead to show the influence of these parameters by characterization of the casted parts in comparison with a reference sample. This study allowed us to find process parameters responsive of ceroxide formation and to propose some way of improvement to reduce the size and the occurrence of ceroxides.

2

Deoxidation Impact on Non-Metallic Inclusions and Characterization Methods

Nicolini C.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 4

97--102

EN

Deoxidation is an unavoidable step in the elaboration of steel. The study of its influence could improve the quality of low-carbon steel (0.20–0.25 wt.% of carbon). There are many deoxidation methods, and the most-common one consists of adding aluminum. Although it is a classic method, determining the optimal process parameters (quantity, yield, etc.) could be very sensitive. Deoxidation plays a determining role on inclusion cleanliness, especially on sulfide morphology. In order to control the efficiency of deoxidation, different techniques can be used. In this paper, an automated counting procedure on a scanning electron microscope with a field emission gun (FEG-SEM) is presented. This method was applied on samples cast in our laboratory under different deoxidation conditions. According to this, the resulting inclusion population is correlated with the aluminum content to find the optimal process parameters.

3

Two ideal cities of the renaissance: Sabbioneta and Zamość

Nicolini C.

Zeszyty Naukowe Politechniki Poznańskiej. Architektura i Urbanistyka

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2008

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Z. 16

53-59

PL

Artykuł prezentuje koncepcję powstania Sabbionety, jednego z najciekawszych obok Palma Nuovy i Zamościa przykładów miasta idealnego. Ukazano proces powstawania koncepcji założenia w kontekście trendów urbanistyki włoskiej okresu Odrodzenia. Przeanalizowano współczesną strukturę przestrzenną miasta w odniesieniu do historycznego projektu.

4

Citta ideale, obóz naukowy studentów architektury w Zamościu

Bonenberg A., Nadolny A., Janowski M., Leoni G., Pollazo U., Lucchini M., Nicolini C.

Zeszyty Naukowe Politechniki Poznańskiej. Architektura i Urbanistyka

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2008

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Z. 16

5-8

EN

This year' winter has been full o unique experiences, after students from the Faculty of Architecture from the Poznan University of Technology had a chance to participate in an international research camp seminar in Poland. This was a next step in the polish- Italian cooperation which took place between 23th of November and the 2th of December 2007 in city of Zamość. This kind of an urban structure, quite popular in Europe during renaissance has been well thought. Zamość along with Italian Sabbioneta are considered to be the few examples of an ideal city. In conclusion - the camp seminar in Zamość can be counted as a successful one.