The scientific investigation involves the examination of copper alloy nails dated back tothe Roman Age. The artifacts were retrieved from a shipwreck discovered offshore Elbaisland (Italy). Further carbon dating measurements indicated the origin between 140 and300 AD. This work includes a brief overview of the ship’s routes and fortunes in order togive some context to the metallographic investigations. The experimental procedureinvolves the use of both Optical and Scanning Electron Microscopy (OM and SEM) coupledwith EDS and EBSD probes. The attention has been focused on the metallurgical features ofthe nails with the intent of casting some light on the metalwork processes of the RomanAge. The scientific trials revealed a “brazed” joint, which allowed to learn more aboutthe applications of this technique during this historical period. In addition, thetextural analysis yielded a strong work-hardening, evidence of an intense cold shapingprocedure in use by the Roman blacksmiths.

Dans les secteurs industriels de l’énergie et du transport, les structures mécaniquessont soumises à de forts niveaux de contraintes dynamiques qui impactent grandement leniveau de durabilité de ces dernières. Dans un contexte de réduction de coût de possessionet d’extension de durée de vie, les industriels sont conduits désormais à bien maîtriserla fiabilité mécanique de leur produit. Pour ce faire et de part la nature stochastiquedes chargements dynamiques, les méthodes utilisées sont celles de la fatigue vibratoire,basées sur des représentations fréquentielles, tant au niveau du schéma modal de lastructure, qu’au niveau de la définition de ses processus d’excitation et de contrainte.De ces considérations techniques, le présent article fait le tour des méthodes de calculutilisées en fatigue vibratoire et compare les méthodes de comptage Peak-Valley (PV) aveccelles du RainFlow Counting (RFC), reconnues comme les moins conservatives et donc lesplus pertinentes, en terme de prédiction de durée de vie. En ce qui concerne les méthodesPeak-Valley, les modèles historiques de Rice [S.O. Rice, Bell Systems TechnicalJournal 23 (1944) 282-332; 24 (1945) 46-156] et deMiles [J.W. Miles, J. Aeronautical Sci. 21 (1954) 753-762],développées en 1944 et 1954, sont pris comme référence et comparés aux modèles RainFlowCounting de ces dernières années. Pour ce faire, l’étude comparative se basera notammentsur les approches empiriques de Wirsching-Light [P.H. Wirsching, M.C. Light, J.Structural Division ASCE 106 (1980) 1593-1607], et semi-empiriquesde Dirlik [T. Dirlik, Application of computer in fatigue analysis, Ph.D. thesis,University of Warwick, 1985], développées respectivement en 1980 et 1985.

In the general frame of energy saving, environment protection and the concept of circulareconomy, the fundamental research on the sintering technology with super deep bed,achieving energy saving and emission reduction, was carried out. At first, thecharacteristics of the process and exhaust emission in the sintering with super deep bedwas mastered through the study of the influence of different bed depths on the sinteringprocess. Then, considering the bed permeability and the fuel combustion, their influenceon the sinter yield and quality, their potential for energy saving and emission reductionwas studied. The results show that the improvement of the bed permeability and of the fuelcombustibility respectively and simultaneously, leads to an improvement of the sinteringtechnical indices, to energy saving and emission reduction in the condition of super deepbed. At 1000 mm bed depth, and taking the appropriate countermeasure, it is possible todecrease the solid fuel consumption and the emission of CO2, SO2,NOx by 10.08%, 11.20%, 22.62% and 25.86% respectively; and at 700 mm bed depth, it ispossible to reduce the solid fuel consumption and the emission of CO2,SO2, NOx by 20.71%, 22.01%, 58.86% and 13.13% respectively. This researchprovides the theoretical and technical basis for the new technology of sintering withsuper deep bed, achieving energy saving and reduction of emission.

The basic idea of H2-C mixture reduction reflects the advantages of hydrogenfor fast reaction and low heat absorption in a smelting reduction reactor where hydrogenis used as the main reducing agent and carbon as the main heat generator on purpose to cutdown the total energy consumption and CO2 emission. This work aimed at theexperimental investigation of the optimal carbon/hydrogen ratio, a key parameter of ironoxide reduction with mixture reductive agents of carbon and hydrogen. Experiments werecarried out using a pure Al2O3 crucible which was placed in atubular furnace for high temperature. Two investigation methods were adopted: one wasinjecting an acetylene/hydrogen mixture reducing gas into molten iron oxides, and theother was blowing hydrogen into an iron bath during continuous feeding of fine ore mixingsolid carbon. Parameters such as the apparent de-oxidation rate and utilization ratio ofreductive agents were calculated from content analysis of the exhaust gas after dustremoval and drying. In the experiments the highest total de-oxidation rate andsatisfactory apparent utilization ratio of hydrogen were obtained under conditions withtemperatures of 1823 K and the carbon/hydrogen ratio in the region of 0.5:1 to 1:1.