Microalloyed steel applications in high-rate hot forging processes

Worthwhile process savings are obtained in the hot-forging of components by using automated high-rate plants and microalloyed steels that do not require subsequent quenching and tempering. This paper describes and discusses the mechanical and fatigue properties of a series of microalloyed steels. Present and foreseen applications are also reviewed with regard to the automotive industry.Lastly, some suggestions are made concerning the correct choice of materials and components to ensure reliability in the application of this class of steels

La progettazione a fatica in condizioni di sollecitazione pluriassiale: stato della ricerca ed esigenze della realtà industriale

ATA, Vol

Defect tolerant design of automotive components

The problem of the fatigue strength estimation of materials or components containing natural defects, inclusions or inhomogeneities has a great importance either from a scientifical or industrial point of view. An attracting feature of the fatigue strength estimation of components containing defects is undoubtedly the possibility to adopt a new design philosophy and to forecast the fatigue strength of a "fleet" of components that contain various sorts of defects due to the manufacturing process. In this paper we discussed the application of this methodology to the defect tolerant design of automotive components. The components under examination were engine conrods either made of cast iron or made by hot forging in carbon steel. The experiments carried out allowed us to discuss the application of Murakami-Endo's model to industrial components, dealing with variability of material properties and microstructure, residual stresses, methods for the research of defects. The attention was eventually focused on the statistical analysis of defects in order to obtain reliable estimates of maximum defects

Hydrodynamic and hydrogeochemical evaluation of groundwater and linkage with herbicide pollution: Central Argentina

Surface water and unconfined and semiconfined (SAC B) aquifers of Marcos Juárez plain, in the central Pampa of Argentina, were studied to assess hydrogeological features and the presence and distribution of herbicides in water. The studied area, located near a regional hydrological discharge area shows streams and channels of high salinity fed by the groundwater with low values of herbicides as a consequence of hydrodynamic dispersion. The unconfined and semiconfined aquifers (SAC B) are impacted by the presence of herbicides although the percentage of positive samples is low. The unconfined aquifer, directly connected to the atmospheric phase, has a shallow water table being more likely to be reached by effective water infiltration. Despite their high Koc and low GUS index, glyphosate and AMPA were present in the highest concentrations in the unconfined aquifer. It is assumed that this situation is the result of its widespread use, its high solubility in water, and its high persistence. The chemical characteristics of metolachlor and imazethapyr, such as their relatively low Koc, moderate and high GUS index, and high persistence have allowed also their leaching into groundwater. Herbicide migration from the unconfined aquifer to the semiconfined aquifer layer in the loessical plain can occur due to the differences in their hydraulic potential. This situation facilitates the mixing of water, a process that is interpreted through fractures or cracks in the confining units (aquitards) or due to the presence of broken old pipes. The multivariate statistical analysis of the unconfined groundwater chemistry leads us to the conclusion that approximately 53% of the variance is explained by different levels of salinization resulting from natural geochemical processes (such as cation exchange, dissolution of salts, etc.), while the remaining 47% is attributed to contamination processes (arrival of herbicides and nitrates). The second and third positions of herbicides in the PCA analysis demonstrate the impact of agricultural activity, especially in the unconfined aquifer.Fil: Giacobone, Daniela Beatriz. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Lutri, Veronica Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; ArgentinaFil: Blarasin, M.. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; ArgentinaFil: Matteoda, E.. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; ArgentinaFil: Cabrera, A. E.. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; ArgentinaFil: Bécher Quinodóz, Fátima Noelia. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Schroeter, G.. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; ArgentinaFil: Pramparo, Santiago Javier. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Pascuini, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Departamento de Geologia. Cat.de Hidrogeologia; Argentin