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La soldadura subacuática mojada, usando el proceso manual con electrodorevestido (SMAW), es actualmente la técnica más empleada para realizar trabajos de reparación en condiciones subacuática (mojada), debido a las características de maniobrabilidad propias del proceso. El revestimiento es la parte estructural del electrodo que más influye sobre su campo de aplicación, por tanto su impermeabilización es requisito indispensable, la cual se realiza mediante la aplicación de capas impermeables sobre el mismo, utilizándose habitualmente para esta operación resinas, ceras, parafinas o barnices. En eltrabajo se presenta una evaluación preliminar, acerca del uso del poliestireno reciclado como alternativa para la fabricación de un impermeabilizante para estos electrodos, abordándose las características principales de su preparación y forma de aplicación. Para realizar la evaluación de este nuevo impermeabilizante, se realizaron depósitos de soldadura en lámina de aguay a 50 m de profundidad, comparándose el desempeño de los electrodos impermeabilizados con el barniz tradicional y con la nueva formulación, fundamentalmente en lo referido a la apariencia superficial del cordón y a la formación de poros en el metal depositado a 50 m de profundidad, además fue realizada la caracterización química a los depósitos obtenidos en lámina de agua. La evaluación preliminar evidenció la factibilidad de emplear el poliestireno expandido como material alternativo para la fabricación de impermeabilizante para los electrodos empleados en operaciones de soldadura subacuática mojada.

Underwater wet welding, using shield metal arc welding (SMAW) manual process with coated electrode, is currently the most widely used technique for repair working in underwater wet conditions because its easy maneuverability characteristics. The coating is the structural part of the electrode with the greatest influence on its scope, so that its waterproofing is a prerequisite, which is performed by applying impermeable layers on it, commonly used for this operation, resins, waxes, paraffins or varnishes. This paper presents a preliminary assessment regarding the use of recycled polystyrene as an alternative for waterproof for these electrodes, addressing the main features of their preparation and application form. To evaluate this new waterproof, weld deposits were made with coated electrodes painted with polystyrene at a water depth of 50 m, comparing the performance of it with traditional varnishes, mainly with regard to the surface appearance of weld bead and the formation of pores in the weld metal. The chemical characterization of deposits obtained at a water depth also was performed. The preliminary results of the evaluation showed the feasibility of using expanded polystyrene as an alternative material for the manufacture of waterproofing for the electrodes used in underwater wet welding.

The use of feeding aids in the foundry process has become widespread globally recent decades, leading to increased efficiency. This article examines the characterization of rice husks, their ashes, and their positive impact as hot topping on the efficiency of open risers in casting cylindrical parts made of AISI 1045 steel. The rice husks were analyzed through X-Ray Diffraction test, Thermal-Gravimetric Analysis, and Differential Thermal-Gravimetric Analysis, while the ashes were characterized using X-Ray Diffraction. The analyzed rice husks were found to contain cellulose and low crystallinity silicon, whereas the ashes primarily consisted of cristobalite and tridymite. It was observed that the thermal decomposition of rice husks occurs in three stages, with approximately 81% of the mass lost during their combustion as hot topping on liquid steel. The location of cavities contraction in the risers of casting parts was made through longitudinal cut of the part-riser system. The increase in the rice husks topping layer thickness positively influences the concentration of these cavities on the upper surface and enhances the feeder's efficiency.