The present work studied the characterization of boriding coatings without and with exposed hydrogen permeation on AISI 8620 through microstructure and mechanical behavior. A dehydrated paste pack process was carried out for the formation of boride coatings on AISI 8620 at 1173, 1223, and 1273K for 6h of exposure time for each temperature. After boronizing, hydrogen was introduced into the borided steels by in situ cathodic charging using an H2SO4 acid electrolyte. Specimens borided without and with hydrogen were characterized by scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction. The experimental techniques of the Vickers microhardness and three-point bending were used. As a result, the hydrogen diffusion on steel AISI 8620 borided shows a significant increase in microhardness. Furthermore, three-point bend tests showed an increased strength on 8620 steel borided. However, the ductility and strength value on 8620 steel borided surfaces presented a drastic reduction due to hydrogen permeation. The results revealed that the borided coatings provided strength and reduced the hydrogen embrittlement index on AISI 8620 borided.
The study of wear is currently one of the most important aspects of applied mechanics. The damage caused by this phenomenon involves the total replacement of parts in devices ranging from industrial machinery to biomedical implants. The focus of these work is aimed at the analysis and prediction of mechanical wear in prostheses manufactured using UHMWPE materials and 316 LVM stainless steel by means of the finite element method using Abaqus® software V. 2020. The wear mechanism between the surfaces of the UHMWPE material specimen and a 316 LVM stainless steel specimen was modeled using Archard’s wear theory to determine the parameters of damage, plastic deformation, and fatigue. The attrition process was discretized into several steps, including developing a program in Fortran code, and integrating a pre-established subroutine known as UMESHMOTION, followed by a Mesh update whenever contact nodes were deformed. For the simulation process, the variables of the thermal properties of conductivity, specific heat, and the parameters of the Johnson-Cook plastic model were taken into account. The simulation results were validated by laboratory tests.
This work studies the mechanical behavior of microalloyed steels (API X60 and API X70) with boride layers using a boriding process and immersion in diesel. First, the microalloyed steels were borided using dehydrated boron paste at a temperature of 1273 K for 6 h, and then the borided microalloyed steels were immersed in diesel for one year. The characterization of the layers on the specimens subjected to diesel used scanning electron microscopy (SEM), energy dispersive spectroscopy, and X-ray diffraction (XRD). The evaluation of the mechanical properties was performed with tensile tests according to ASTM E8, and then the fracture surface was observed by SEM. This work contributes to the understanding of the changes in the mechanical properties of borided microalloyed steel immersed in diesel for possible potential applications in the storage of fuels, oils, hydrogen, and biofuels.
12 April 2024 in Pädi Boletín Científico de Ciencias Básicas e Ingenierías del ICBI
La soldadura por ultrasonido (USW) es utilizada en la manufactura de componentes automotrices, este proceso presenta ventajas, es un proceso eficiente, con consumo de energía bajo, sus herramentales tienen largo tiempo de vida y poco mantenimiento. El proceso de soldadura ultrasónica se caracteriza porque las superficies de contacto vibran con frecuencias ultrasónicas simultáneamente aplicando presión externa para aumentar la fricción. Usando las relaciones de la literatura y aplicaciones CAD-CAE integradas, el artículo presenta el diseño y verificación de un sonotrodo utilizado en un sistema ultrasónico para soldadura de dos componentes plásticos que además integra un sistema de posicionamiento por vacío.
Today, the demand for materials with structural applications that meet the needs of the aeronautical and automotive industries is more demanding in terms of corrosion resistance, wear and low density. All this without neglecting the sustainability and recycling of materials.