Discussion on “Stable eutectoid transformation in nodular cast iron: modeling and validation”

The Minerals, Metals & Materials Society and ASM International 2017 Given that cast irons are multicomponent alloys, the decomposition of the high temperature austenite into ferrite and graphite happens within a finite temperature range and not at an invariant point, as often described schematically. Only a few models explicitly consider the existence of such an austenite–ferrite–graphite range: the contribution under discussion,[1]those that inspired it[2,3] and one previous study from the present author.[4]For kinetics reasons, this latter work explained that ferrite could not grow within the equilibrium three-phase field under continuous cooling; this is in contradiction with the other three reports. The aim of this discussion is first to recall the experimental evidence about ferrite formation during eutectoid transformation of cast iron and then to provide an explanation as to why ferrite starts forming upon cooling only when the temperature of the material is below the equilibrium three-phase field range, as observed experimentally

Synthesis and Spectral Studies on Cardanol Based Polyurethanes

Cardanol is a renewable organic resource obtained as a byproduct from the cashew industry. The present study has been carried out with an aim to manufacture rigid polyurethanes from natural and eco – friendly sources due to the rising prices of petrochemicals and also as an environmental concern. Vegetable oil based polyurethanes promising a new generation polymers which are low cost materials in the family of polyurethanes. Cardanol based phenolic resin has been synthesized by condensing cardanol with furfural in a particular mole ratio using phthalic acid as catalyst. The progress of the reaction was monitored by determining the free furfural and free phenol content. The resin was cured by using the curing agent 4, 41 - methylene bis(cyclohexyl isocyanate) and the catalyst dibutyltin dilaurate to produce polyurethane. Polyurethanes are an important class of polymers that have found place in many applications. The physico chemical and spectral properties of resin and polyurethane have also been studied

Georges Ohnet, Filmographie

Elaboració del llistat de pel·lícules que s’han realitzat sobre les novel·les d’aquest autor.Elaboration de la liste de films tirés des romans de cet auteurElaboración de la lista de películas realizadas a partir de las novelas de este autor.Development of the list of films from novels by this author

3D visualization tools to explore ancient architectures in South America

[EN] Chan Chan is a wide archaeological site located in Peru. Its knowledge is limited to the visit of Palacio Tschudi, the only restored up to now, whilst the majority of the site remains unknown to the visitors. The reasons are manifold. The site is very large and difficult to visit. Some well-conserved architectures, such as Huaca Arco Iris, are very far from the core centre. Furthermore, there are heavy factors of decay, mainly caused by illegal excavations, by marine salt and by the devastating phenomenon of El Niño. For these reasons, the majority of the decorative elements are protected by new mud brick walls. Finally, the vastness of the buildings makes difficult to understand their real value, even through a direct visit of the site. In order to overcome the aforesaid problems, we designed, developed and realized the museum exhibition presented in this paper. We named Esquina Multimedia an installation where every corner is aimed to solve a specific problem, providing the tourists with interactive and enjoyable applications. The virtual tour allows reaching also the unreachable areas. An Augmented Reality (AR) application has been developed in order to show ancient artefacts covered by the earth. A web-browser has been specifically designed to show bas-reliefs, with HD visualization, anaglyph stereoscopic view and a 3D virtual model of both the structures and the bas-reliefs. At the same time, a wall-mounted panel representing a metric 3D reconstruction of the building helps the user to find the artefact position. Descriptions of the hardware components and of the software details are presented, with particular focus regarding the implementation of the application, arguing how the digital approach could represent the only answer towards a full exploitation of archaeological sites. The paper also deals with the implementation of a web tool, specifically designed to display and browse 3D-Models.Pierdicca, R.; Malinverni, ES.; Frontoni, E.; Colosi, F.; Orazi, R. (2016). 3D visualization tools to explore ancient architectures in South America. Virtual Archaeology Review. 7(15):44-53. doi:10.4995/var.2016.5904.SWORD445371

Effect of Cu, Mn and Sn on pearlite growth kinetics in as-cast ductile irons

In a previously published work, pearlite growth in cast irons was investigated and it was claimed that growth kinetics of pearlite in nodular cast iron does not depend on alloying elements and that only the start temperature for the transformation is modified. Since then, the authors have investigated the effect of copper at low level of manganese and the combined effect of copper and tin at intermediate manganese contents. In the first case, thermal records confirmed that copper decreases the formation temperature for both ferrite and pearlite. In the second work, an optimised content for tin, manganese and copper was found so as to improve mechanical properties while keeping fully pearlitic structures. The thermal records obtained during this latter study are here used to estimate the pearlite growth kinetics and the effect of copper and tin on it. Tin has been shown to reduce pearlite undercooling (increase of start transformation temperature) and thus to favour the formation of this constituent

About Equilibrium Mode Ruling Ferritic Transformation in Low-Alloy SGI

Ferrite precipitating around the graphite nodules shaping the typical bull’s-eye microstructure could grow under negligible partitioning local equilibrium or under paraequilibrium conditions, as both imply that ferrite inherits the composition of the parent austenite. The first mechanism has been rejected by other researchers by means of simple calculations of the silicon spike width necessary for local equilibrium conditions to take place. Nevertheless, experimental analyses are necessary to verify this conclusion. In this study, transmission electron microscopy has been used to assess the presence of a silicon spike in front of the growing ferrite interface. The outcome allowed the authors to confirm that a paraequilibrium mode governs the transformation, supporting the conclusions of previous calculations. In addition, some issues about ferrite growth modeling are discussed.Fil: García, Laura Noel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Mecánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Carazo, Fernando Diego. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Mecánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Boeri, Roberto Enrique. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Mecánica Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin