Journal articles: 'Billetes'

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Montoya-de la Cruz, Stephany, and Graciela Pereyra-Fausto. "Nueva familia de billetes (Banco de México)." Boletín Científico de la Escuela Superior Atotonilco de Tula 6, no. 11 (January 5, 2019): 54–55. http://dx.doi.org/10.29057/esat.v6i11.3698.

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El presente artículo explica la función constitucional que ejerce el Banco de México por medio del mandato constitucional de proveer moneda nacional al país, es la única institución autorizada para la creación y emisión de monedas y billetes, fundado en 1925. Tiene en proceso una nueva familia de billetes, el billete con la denominación de 500 será el primero en circulación.

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Richard Wagner and Carmen Gómez García. "Billetes, and: Entonces." Sirena: poesia, arte y critica 2009, no. 2 (2009): 101–3. http://dx.doi.org/10.1353/sir.2009.0000.

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Acuña Mantilla, Kelly Vanessa, and Andrés Álvarez. "De la moneda metálica al billete de banco en Medellín y Bogotá (1871-1885): complementariedad y sustitución de medios de pago en un régimen de banca libre." Tiempo y economía 1, no. 1 (December 30, 2014): 77–106. http://dx.doi.org/10.21789/24222704.946.

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El estudio de la circulación monetaria durante la llamada era de “banca libre” en Colombia (1865-1885) muestra patrones diferentes según las regiones. Este trabajo estudia la complementariedad y sustitución entre la moneda metálica acuñada legalmente y los billetes de bancos privados. Se pone en evidencia la existencia de mecanismos de sustitución entre monedas de oro y billetes bancarios para el caso de Antioquia, mientras que en el caso de Bogotá no se puede afirmar que la evidencia sea concluyente. El patrón de comportamiento de la acuñación de monedas de plata, por el contrario, muestra complementariedad con el billete de banco en ambas regiones. Este trabajo concluye que en Colombia se presentó una forma de Ley de Gresham particular. Se muestra evidencia que permitiría concluir que las diferenciasregionales en el funcionamiento de este mecanismo se deben a la especialización de la región de Medellín (estado de Antioquia) como mayor productor y exportador de oro, de donde se puede inferir un mayor costo de oportunidad de la circulación de este metal y una tendencia a adoptar más fácilmente formas de moneda fiduciaria. Esto no es completamente cierto para Bogotá, cuya economía se especializa en agricultura, servicios comerciales y artesanado.

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Solache Damián, Karim Israel. "La iconografía política en el papel moneda latinoamericano. Una reflexión del espacio-tiempo en América Latina." Estudios Latinoamericanos, no. 31 (February 25, 2013): 137. http://dx.doi.org/10.22201/cela.24484946e.2013.31.47324.

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El control y la dominación social han adquirido formas cada vez más sofisticadas. En pocas ocasiones observamos la iconografía que yace en ellos y que conforma el imaginario-cívico colectivo de una sociedad. El mundo entero atraviesa desde hace tres décadas una crisis que puede ser leída a través de las imágenes plasmadas en los billetes que usamos cotidianamente. Asimismo, el neoliberalismoy la globalización, fenómenos que aquejan a Latinoamérica, pueden ser narrados a través de laiconografía política. Hoy podemos ver que los cambios político-económicos, operados desdela cúpula del poder, han tenido un relato casi paralelo en las imágenes halladas en los billetes tanto mexicanos como latinoamericanos. La propuesta es indagar cuál es el medium que se expresa en una historia codificada en los billetes y desentrañar sus más obscuros secretos sin dejarnos atrapar por su discurso. Decodificar la iconografía política con relación al espacio-tiempo latinoamericano es el reto.

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Montero Mora, Andrea. "Reseña del libro: Billetes. Del papel moneda a los billetes de banco en Costa Rica, de Manuel Chacón Hidalgo." Revista de Historia, no. 82 (July 1, 2020): 153–60. http://dx.doi.org/10.15359/rh.82.5.

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Se reseña aquí un trabajo sobre historia económica, centrado en el estudio de la moneda y el dinero. Es un trabajo de divulgación científica que analiza el proceso de consolidación de la moneda en Costa Rica desde el siglo XVIII hasta el año 2018. Esta periodización está ordenada cronológicamente en seis épocas distintas, que concuerdan con los seis capítulos en que se divide el libro. Además de esta periodización de la historia de la moneda, el texto ofrece dos hipótesis sobre los usos de la moneda; primeramente como mecanismo de control social, y segundamente como elemento de cambio cultural con la llegada del papel moneda.

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Ródenas, Clementina, and Segundo Bru. "La convertibilidad de la peseta en el siglo XIX." Revista de Historia Económica / Journal of Iberian and Latin American Economic History 24, no. 3 (2006): 555–78. http://dx.doi.org/10.1017/s021261090000063x.

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ResumenEste artículo presenta una nueva interpretación para una cuestión central de la historia monetaria española. En España, desde el Decreto de Figuerola de 1868, el sistema monetario legal era, y continuó siendo a lo largo de todo el siglo XIX, bimetalista. Como consecuencia de tal sistema el Banco de España, al igual que el Banco de Francia, podía realizar el pago de sus billetes en plata, en oro, o en ambas monedas metálicas. Por ello, en 1883 no hubo ninguna declaración de inconvertibilidad ni el abandono de ningún supuesto patrón oro. La convertibilidad de la peseta, que no puede identificarse exclusivamente con su canje por oro, siempre estuvo asegurada por las leyes y por la jurisprudencia. En España, a diferencia de Italia, Portugal, Austria o Francia, no hubo nunca curso forzoso del billete.

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Alexeevich Prakht, Vladimir, Vladimir Alexandrovich Dmitrievskii, Fedor Nikitich Sarapulov, Anton Aleksandrovich Dmitrievskii, and Nail Ramazanovich Safin. "Computer-based modeling of moving cylindrical ferromagnetic billets induction heating." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 33, no. 1/2 (December 20, 2013): 273–85. http://dx.doi.org/10.1108/compel-09-2012-0182.

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Purpose – Nowadays, various software is available for simulating physical processes in induction heating. The software is often limited in its ability to simulate the billet movement, sometimes assuming uniform distribution of voltages on the inductor winding, uniformity of the physical properties of the billet, etc. The mathematical model of moving cylindrical ferromagnetic billets described in this paper takes into account the billet's movement, the billet phase heterogeneity and the nonuniformity of the supply voltage distribution in the inductor turns. The paper aims to discuss these issues. Design/methodology/approach – The research methodology is based on FEM analysis of the coupled problem, including the electromagnetic and thermal boundary problem with additional algebraic equations, using Comsol 3.5a software. Findings – The electromagnetic and temperature field in the billet and the voltage distribution on the winding turns have been calculated. The phase distribution in the billet has been predicted. Significant interaction of the nonuniformity of the supply voltage distribution, the billet's movement, the billet phase heterogeneity and side effect on the ends of the inductor have been shown. Practical implications – The results received can be used for designing the induction heating unit for moving cylindrical billets made from ferromagnetic material and improving their characteristics. Originality/value – Investigation of moving cylindrical ferromagnetic billets induction heating can be done by numerical solving the coupled problem including the electromagnetic and thermal boundary problem with additional algebraic equations for the supply voltage distribution.

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Betancur, Carlos Alberto, Santiago Estrada, María Teresa Ceballos, Elisa Sánchez, Ana María Abad, Claudia Vanegas, and Lina María Salazar. "Billetes como fómites de bacterias con potencial patógeno para el hombre." Infectio 14, no. 2 (June 2010): 120–26. http://dx.doi.org/10.1016/s0123-9392(10)70100-4.

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Samusev, S. V., and V. A. Fadeev. "Modeling of longitudinal welded pipe forming in open rolling pass unit of electric weld pipe mill." Izvestiya. Ferrous Metallurgy 62, no. 7 (August 22, 2019): 531–38. http://dx.doi.org/10.17073/0368-0797-2019-7-531-538.

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The results of theoretical and physical modeling of pipes forming process are described. Experiments on strip billets forming were carried out on 10-50 pipe-welding mill for a pipe 50 mm in diameter with 1mm wall. Forming of pipe billets was carried out at unit of forming horizontal and vertical stands with estimation of geometrical parameters. Roll drafting is one-radial. Energy-power parameters of the process that affect quality of billet geometry were determined and measured. Analysis of geometric parameters of resulting billet has revealed defects of buckling type on the billet’s right edge between the second edger and the third molding stand. Similar defect was detected at the left edge of the billet at a distance of the third molding and edger stands. To eliminate defects in forming section, shaping stands were rebuilt so that forces on drive cells were identical. Energy-force parameters of the process were sequentially determined: pulling forces of drive stands, resistance to strip movement and vertical molding forces. Calculations for determining energy-force parameters were performed taking into account the main technical parameters using two methods. The first technique takes into account geometric parameters of molded billet and parameters of working zone with the zone of non-contact deformation. The second method is based on consideration of contact interaction between the billet and shaped instrument along the deformation section. Discrepancy between calculated and experimental data was 8 – 12 %. After adjusting technical parameters of the molding process and the passes re-adjusting, a defect-free pipe billet was formed. Comparative analysis of calculated and experimental edge trajectories along the height and width of the cages showed discrepancy in results in range of 6 – 9 %. While studying geometric parameters of the focus of deformation, contact and non-contact zones of working zone and area of sprinkling were taken into account. Parameters of the pipe billet shaping in monotonous and roll forming centers have been calculated. Analysis of the results has shown that change in billet’s geometry in shaping stand corresponds to the accepted statements of billet’s geometry changes in rolling pass.

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Smirnov, E. N., V. A. Sklyar, A. N. Smirnov, V. A. Belevitin, and R. E. Pivovarov. "Influence of thermal state of the end area of multiple continuous-cast billet on cracking of the ends of hot-rolled breakdown at rolling." Izvestiya. Ferrous Metallurgy 62, no. 7 (August 22, 2019): 539–47. http://dx.doi.org/10.17073/0368-0797-2019-7-539-547.

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The authors have made an analysis of problems arising in the rolling of continuous-cast billets in the modern mini-metallurgical and rerolling plants. It is shown that the use of trio stands in rolling mills of these plants makes it necessary to obtain billets of multiple lengths from bars (most often of 12-meter length) produced in the rolling shop. The subsequent rolling of such multiple billets has revealed increased cracking of the front edge and, as a result, increased metal consumption. Analysis of the causes of these cracks has been made. It was indicated that this defect can appear as a result of a certain stress-strain state formed at the end of hot-rolled breakdown. It is caused by the presence of an uneven temperature field due to more intensive end cooling, to reduction mode in the trio stand and to the presence of axial defects in the continuous-cast billet. The study was conducted on the industrial medium-grade mill 500/370, as well as using mathematical modeling by finite element method. The influence of a set of technological factors, such as temperature of the billets heating before rolling, the time interval of their transportation on the site “heating furnace – first stand of the rolling mill” and parameters of the macrostructure of axial area of the metal were investigated. Calculations by the developed mathematical model have indicated the need to take into account the presence of a scale layer on the heated continuous-cast billet. It is shown that depending on the heating temperature and transport time, the temperature difference at the billet’s end compared to the heating temperature can be from 45 to 100 °C. It will lead to an uneven distribution of deformation resistance and unfavorable stress-strain state at the billet’s end. In addition, the presence of an axial defect can affect the cracking because of its shape and its transformation during reduction. Obtained experimental data allowed hypothesizing the mechanism of transformation of discontinuity defects into cracks at the billet’s end due to the conditions of continuous casting and cutting of billets during rolling in the reduction stand.

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Recalde-Reyes, Delia Piedad, Natali Alfonso-Ortiz, Michael Farley Fuentes-Quimbayo, Valeria Ángel-Hernández, Ivonne Guzmán-Ladino, Jesús Fabricio Medina-Manrique, and Carlos Andrés Rodríguez-Salazar. "Perfil de resistencia genotípica y fenotípica presente en bacterias aisladas a partir de fómites en Armenia, Quindío-Colombia período junio-julio 2019." Infectio 25, no. 1 (September 6, 2020): 22. http://dx.doi.org/10.22354/in.v25i1.904.

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Introducción: La antibiótico-resistencia es un fenómeno por el cual las bacterias logran sobrevivir al tratamiento con antimicrobianos; con incidencia en ambientes intra y extrahospitalarios como: fuentes hídricas, sector agrario/ganadero y fómites. Objetivo: Describir bacterias presentes en fómites de alta circulación en una región centro-occidental de Colombia junto a su perfil de sensibilidad fenotípica y presencia de genes para betalactamasas tipo TEM-full, OXA-3 y SHV-full. Metodología: Se aislaron cepas bacterianas de billetes, pasamanos de escaleras eléctricas y botones de cajeros automáticos; se evaluó su perfil de sensibilidad fenotípica por medio de concentración mínima inhibitoria-técnica automatizada/Vitek2® y genes para betalactamasas tipo TEM-full, OXA-3 y SHV-full mediante PCR convencional. Resultados: Se obtuvo 30 aislados; Acinetobacter baumannii complex, fue la más común; el fómite con mayor aislados y resistencia fueron los billetes; el 53% portó al menos uno de los genes estudiados. Se identificaron bacterias gramnegativas con resistencia frente a: Imipinem, Piperacilina/Tazobactam, Colistina, Ceftazidima, Tigeciclina y Ceftriaxona; bacterias grampositivas con resistencia frente a: Quinupristina/Dalfopristina, Minociclina, Tetraciclina, Teicoplanina, Nitrofuratoina, Oxacilina, Clindamicina, Trimetropina-sulfametoxazol, y Minociclina. Conclusión: Teniendo en cuenta la circulación de cepas con estas resistencias, es importante la educación en la comunidad para evitar la adquisición o propagación de infecciones por manipulación inadecuada de fómites.

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Galeano, Diego. "El clan Chiarini: migración y falsificación de dinero en América del Sur, 1890-1910." Historia Mexicana 70, no. 3 (December 10, 2020): 1281. http://dx.doi.org/10.24201/hm.v70i3.4184.

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Por medio de la trayectoria de una familia de italianos dedicados al negocio de la fabricación y circulación de dinero falso, este artículo revisita el problema del vínculo entre migración y delito en la América del Sur del cambio de siglo. Tomando distancia de la historiografía que aborda ese nexo como un tópico criminalizante del discurso de las elites (políticas, jurídicas y médicas), sugiere tomar otro camino: al interrogarse por la perspectiva de los propios falsificadores, surgen nuevas preguntas sobre la manera en que los inmigrantes se relacionaban con el dinero en las fronteras tenues entre estrategias legales e ilegales de acumulación. El mercado de los billetes falsos permite entrar a ese mundo atravesado por confianzas y desconfianzas, transacciones y traiciones, solidaridades étnicas y lazos de parentesco. A los fabricantes, intermediarios y circuladores de billetes falsos se le suman otros actores clave como detectives policiales, agentes diplomáticos, cronistas de la prensa, comerciantes y funcionarios de los bancos. De esos múltiples cruces surgen las principales fuentes documentales del trabajo: escritos policiales y periodísticos, archivos judiciales y diplomáticos de distintas ciudades del espacio atlántico sudamericano dan cuenta de las conexiones transnacionales que marcaban el ritmo de este negocio de la falsificación de dinero.

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González-Millan, Julio Cesar, and Luis Fernando Guardiola-Plazas. "La Confiabilidad en las Monedas Digitales como Inversión Práctica en la Economía del Futuro." Reflexiones contables (Cúcuta) 2, no. 2 (July 1, 2019): 102–14. http://dx.doi.org/10.22463/26655543.2990.

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En el mundo de la era tecnológica, las monedas digitales están marcando el inicio de una revolución industrial que podría llamarse revolución de las criptomonedas, cada país le da su valor sobre la economía funcional que posee, y tiene una moneda para comercializar a través de la tecnología digital, lo que presumiblemente hasta hoy es una evolución de monedas intangibles, y está desplazando los billetes, pero que también se están imprimiendo billetes sobre criptomonedas, lo que quiere decir que es dinero efectivo, seguro y práctico. En el presente trabajo se realiza proponiendo como objetivo general: Determinar la confiabilidad en las monedas digitales como inversión práctica en la economía del futuro. Se realizó una investigación tipo documental y descriptiva, de análisis, basadas en revistas, fuentes de internet, informes, y libros respecto al tema. Se concluye que la confiabilidad de la moneda es alarmante, respecto a la cantidad de inversiones que están haciendo las personas y los comercios con esta revolución de economía digital, pero que el dólar es difícil que se desplace, porque casi todos los países del mundo comercializan sus productos con esta divisa, y Colombia cuenta con proyecciones de cambiar su moneda colombiana, dada a conocer la criptomoneda Triskel, aunque lo difícil no es crearla sino mantener su poder de convencimiento.

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Zaides, S. A., and L. Kh Kuang. "STRAIGHTENING OF LOW-RIGID CYLINDRICAL DETAILS. PART 2. STRESSED STATE OF CYLINDRICAL BILLETS AT TRANSVERSE CHEESING BY FLAT PLATES." Izvestiya. Ferrous Metallurgy 62, no. 9 (October 23, 2019): 674–80. http://dx.doi.org/10.17073/0368-0797-2019-9-674-680.

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To restore the shape of curved low-rigid cylindrical details such as shafts and axles, bending straightening under distributed loading is proposed, followed by hardening of the billet using surface plastic deformation based on transverse cheesing of it by flat plates. It is known that after straightening by transverse bending, non-equilibrium stresses are formed over the entire volume of the billet and over time the shape of the detail may again be distorted. Therefore, after performing the straightening process by bending, it is necessary to additionally strengthen the billets by surface plastic deformation based on the transverse cheesing of them by flat plates. The aim of the work was to determine the condition of capture and stress state of the billet during such transverse cheesing. We used the mathematical apparatus and software package Ansys Workbench. The novelty of the work is a new way to manage the stress state when straightening cylindrical billets. As a result, the value of the capture limiting angle α is in the range of 2 – 8°. Maximum value of the absolute reduction depends on friction coefficient and diameter of the billet. Optimal value of the absolute compression is in the range of ΔH = 0.07 − 0.15 mm. The calculation results have shown that after transverse cheesing, in the center of the billet’s cross section there is a stress state of all-round tension, and a stress state of compression is formed in the billet’s shell. The method of hardening by transverse cheesing with flat plates eliminates the cracks formation and material destruction in the central part of cylindrical products.

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Peeters, Benoit. "Fra billede til billede." MedieKultur: Journal of media and communication research 15, no. 30 (September 4, 1999): 6. http://dx.doi.org/10.7146/mediekultur.v15i30.1144.

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“Case, planche, recit” repræsenterer Benoit Peeters forsøg på at nytænke den teoretiske tilgang til tegneserier i forhold til semiotikkens og strukturalis- mens dominans på området i 70'erne. Benoit Peeters afviser således den strukturalistiske modeltænkning og tilstedeværelsen af strukturer, der skulle eksistere uafhængigt af betydning og kontekst og angiver i stedet en analy- tisk tilgang, “formationnisme”, der sammentænker en billedgrammatik med tegneseriens æstetiske innovationer. I “Fra billede til billede” analyseres et særligt træk ved tegneserien, billedets eksistens blandt andre billeder.

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Flores-Mendoza, Juan Pablo, Alfonso Rojas-Domínguez, Rafael López- Leyva, Manuel Ornelas-Rodríguez, and Raúl Santiago-Montero. "Segmentación automática de billetes mexicanos basada en un modelo de color y referencias geométricas." Research in Computing Science 114, no. 1 (December 31, 2016): 97–110. http://dx.doi.org/10.13053/rcs-114-1-8.

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Jiang, Ju Fu, and Shou Jing Luo. "Research on Thixoforging Magazine Plate of AZ91D Magnesium Alloy in Semi-Solid State." Solid State Phenomena 116-117 (October 2006): 267–70. http://dx.doi.org/10.4028/www.scientific.net/ssp.116-117.267.

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The thixoforging process in which magazine plates of AZ91D magnesium alloy were thixoforged in semi-solid state using semi-solid billets prepared by common SIMA method and new SIMA method was investigated. The results show that the pressure has a great influence on the semi-solid billet’s ability to fill die’s cavity. When the pressure is 500KN, the semi-solid billet can’t fill the die’s cavity completely. When the pressure is 2000KN, the semi-solid billet can fill the die’s cavity completely. Room temperature mechanical properties, such as yield strength of 201.4MPa, ultimate tensile strength of 321.8MPa and elongation of 15.3%, can be obtained successfully when the technological parameters, including pressure of 200KN, die preheating temperature of 723K, holding for 20min at 818K, are satisfied. Comparing with common SIMA, mechanical properties of room temperature and high temperature at 373Kare enhanced heavily.

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Gil Soriano, Alberto. "La creación de nuevos impuestos como forma de financiar el desarrollo. Propuestas recientes." Direito e Desenvolvimento 2, no. 4 (May 23, 2017): 213–45. http://dx.doi.org/10.26843/direitoedesenvolvimento.v2i4.186.

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Los Objetivos de Desarrollo del Milenio son unas medidas decisivas para combatir la pobreza mundial, promovidas por la ONU y compartidas a nivel internacional que precisan de una gran cuantía de recursos para cumplirse. El llamado Consenso de Monterrey sobre la financiación para el desarrollo y la Declaración de Doha sobre la financiación para el desarrollo reconocieron la utilidad de considerar fuentes innovadoras de financiación. En el presente artículo estudiaremos las propuestas más importantes de creación de nuevos impuestos como instrumentos para obtener recursos para financiar el desarrollo. Palabras clave: Objetivos de Desarrollo del Milenio. Consenso de Monterrey sobre la financiación del desarrollo.Impuesto sobre las transacciones financieras.Impuesto sobre los billetes de avión.

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Missaglia, Marco. "Dollarization: Some theoretical preliminary thoughts." Revista Economía 68, no. 108 (December 21, 2019): 59–73. http://dx.doi.org/10.29166/economia.v68i108.2021.

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En este artículo se argumenta que la dolarización introduce una asimetría fundamental en la forma cómo la política macroeconómica puede —o no puede— ser conducida. Cuando las cosas van bien, es perfectamente posible enfriar la economía y conducir una política keynesiana contracíclica estándar. Sin embargo, cuando las cosas van mal, una política expansionista contracíclica no puede ser ejecutada, lo cual complica la probabilidad de ser capaz de acomodar la demanda creciente de billetes y evitar un caos financiero. Todo esto posee profundas consecuencias distributivas y, en particular, favorece a la clase rentista —capitalistas financieros—, haciendo imposible —o extremadamente difícil— acercarse a la eutanasia keynesiana del rentista en favor de un proceso más sostenido de progreso económico y social. Estas conclusiones se basan en la perspectiva teórica clásica de Smith, Ricardo, Marx y Sraffa.

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Zhang, Zhi Qiang, Qi Chi Le, and Jian Zhong Cui. "Direct Chill Casting of Φ500mm ZK60 Magnesium Alloy Billets under Low Frequency Electromagnetic Field." Materials Science Forum 686 (June 2011): 26–29. http://dx.doi.org/10.4028/www.scientific.net/msf.686.26.

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Effects of low frequency electromagnetic field on surface quality, microstructure and hot-tearing tendency of direct chill casting of Φ500mm ZK60 magnesium alloy billets were investigated. The results show that with the application of the low frequency electromagnetic field, the surface quality of Φ500mm ZK60 magnesium alloy billets has been markedly improved, and the depth of cold fold is decreased. In the conventional direct chill casting, the microstructures of the billet, especially at the center, are coarse. The distribution of the grain size is non-uniform throughout the billet. From the edge to the center, the microstructure gradually changes from fine to coarse in all billets. However, under the low frequency electromagnetic casting, the microstructures of the billet is significantly refined, the distribution of the grains size is relatively uniform from the billets edge to the billets center. And it also shows that the hot-tearing tendency of direct chill casting Φ500mm ZK60 magnesium alloy billets under low frequency electromagnetic field is significantly reduced.

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Stolyarov, A. M., A. M. Retunskaya, M. G. Potapov, and M. V. Potapova. "Effect of steel casting speed mode on quality of continuously casted billet." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 75, no. 4 (May 18, 2019): 460–64. http://dx.doi.org/10.32339/0135-5910-2019-4-460-464.

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The speed of billet withdrawal from a continuous caster (CC) mold has a decisive effect on the CC productivity. However, increase of the speed results in an increase of pollution of the CC metal by non-metallic inclusion and increase of surface defects of CC billet. Estimation of steel casting speed mode impact on the degree of different defects formation presented for long products CC billets, casted at a five-strand CC of radial type. Defects of CC billet from Ст3сп steel grade studied for a billet having section of 150×150 mm. The purpose of the study was to determine the degree of influence of withdrawal speed, metal chemical composition and billets cross section dimensions on billets quality. Array of industrial data of more than 550 billets studied, 80.4% of which were casted by an open stream and the balance – by a closed stream. As a result of the CC billets quality study it was confirmed, that during metal casting by an open stream the degree of evolution of form defect, like rhombic defects, internal and surface defects is higher comparing with those when casting by a closed stream. General tendency of increase of the CC metal pollution by non-metallic inclusions at the increase of billet withdrawal speed. The tendency is similar for both casting by an open and by a closed stream. However, during casting by an open stream the increase takes place rather evenly. During casting by a closed stream a sharp increase of billets with defects were observed at the billets withdrawal speed exceeding 2.4 m/min. Linear dependencies of billets withdrawal speed while casting by a closed stream on the degree of liquation cracks evolution and general strips, edge point pollutions and peripheral fine structure metal zone thickness determined. To improve the long products billets surface, casted by a closed stream, it was recommended to restrict the withdrawal speed of the billet from a carbon steel of general quality by the value of 2.4 m/min.

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Feys, Torsten. "Prepaid tickets to the New World: the New York Continental Conference and transatlantic steerage Fares 1885–1895." Revista de Historia Económica / Journal of Iberian and Latin American Economic History 26, no. 2 (2008): 173–204. http://dx.doi.org/10.1017/s0212610900000318.

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RESUMENEste artículo examina la situación de los cárteles del transporte naviero (conferencias) que regularon el transporte migratorio transatlántico del continente europeo a los Estados Unidos. El objetivo del artículo es identificar las presiones internas y externas subyacentes a estos acuerdos, así como las estrategias empleadas para neutralizar estas presiones. El autor llega a la conclusión de que un acuerdo sobre la división del mercado en quatos (market shares) era esencial para la eficacia de la Conferencia, que era al mismo tiempo una forma de integración horizontal que regulaban la competencia entre las compañías de transporte naviero, así como una integración vertical para obtener el control sobre la red de agentes transatlánticos de venta de billetes a la emigración. El autor correlaciona también la eficacia de los acuerdos con las tarifas para emigrantes y los costes de la migración.

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Zhang, Hong Liang, Guang Hong Feng, Bao Shan Wang, Xu Ming Liu, and Xin Liu. "Application of Queuing Theory in Production Efficiency of Direct Rolling Process of Long Product." Materials Science Forum 977 (February 2020): 34–41. http://dx.doi.org/10.4028/www.scientific.net/msf.977.34.

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Based on the mathematical method of queuing theory, the queuing model of billets in the direct rolling process of the long product was established, which represented the conveying process of billets at the casting and rolling interface. Using the billets queuing model, the influence of different steel quantity, length, speed and other factors on the average waiting time of a single billet in the direct rolling production process was analyzed. Combined with the temperature drop of billets, the optimal average waiting time for a single billet was determined. The method improved the conveying connection efficiency of the casting-rolling interface and the direct rolling rate of billets.

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Sánchez, Raquel. "La imagen circulante del rey: el sello postal y las representaciones visuales de la nación en España (1849-1882)." Hispania 79, no. 262 (August 22, 2019): 443. http://dx.doi.org/10.3989/hispania.2019.013.

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Los documentos de valor (monedas, sellos, billetes) portan imágenes con referentes identitarios. A través de ellos circula entre la población un discurso político que remite a la nación, la república, la monarquía, el imperio, Europa, etc. Este artículo se propone estudiar este fenómeno en relación con la fijación de una imagen de la nación asociada a la monarquía a través del sello postal. El diálogo entre Estado, Monarquía y Nación a través de la imagen y el texto estampados en el sello nos permite estudiar las consecuencias que estos elementos iconográficos y textuales tuvieron sobre el imaginario político. La cotidiana visualización de la Corona a través del sello postal, con la cabeza del monarca y/o el escudo nacional, había de contribuir a fijar en la mente de los ciudadanos el icono de la nación liberal del que la reina y el rey eran símbolos.

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Kobelev, O. A., M. A. Tsepin, M. M. Skripalenko, and Vladimir A. Popov. "Features of Technological Layout of Manufacture of Unique Mono-Block Large-Dimension Plates." Advanced Materials Research 59 (December 2008): 71–75. http://dx.doi.org/10.4028/www.scientific.net/amr.59.71.

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Blank punch was applied for manufacturing of hollow billets by press piercing. Analysis of piercing by different punches was carried out. Data showing fluctuating of load during piercing and changing of billet’s shape was received.

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Schönbohm, Alexander, Rainer Gasper, and Dirk Abel. "Inductive Reheating of Steel Billets into the Semi-Solid State Based on Pyrometer Measurements." Solid State Phenomena 116-117 (October 2006): 734–37. http://dx.doi.org/10.4028/www.scientific.net/ssp.116-117.734.

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The aim of the paper is to demonstrate a control scheme by which it is possible to reproducibly reheat steel billets into the semi-solid state. Usually a heating program is used to reheat the billet into the semi-solid state. Our experiments showed that this control scheme leads to varying semi-solid fractions from one experiment to the next. To gain information about the billet’s state its temperature is often used since there is a known relationship between the temperature and the liquid fraction. Direct measurement of the temperature via thermocouples is not feasible in a production environment, therefore a radiation pyrometer has been used as a contact-less measurement device. The accuracy of the pyrometer depends heavily on the exact knowledge of the radiation coefficient, which can vary from billet to billet due to different surface properties and which is subject to change during the heating process. These uncertainties prohibit the implementation of a closed-loop control scheme since the exact temperature cannot be measured with the required accuracy. In order to be independent of the measurement errors the proposed control scheme only relies on the slope of the temperature. By detecting the distinct change of slope which occurs when the solidus temperature is crossed, the beginning of the melting process can be determined. The energy fed to the billet from this point onward determines the resulting liquid fraction. By detecting the entry into the solidusliquidus interval and then feeding the same amount of energy to each billet, it is guaranteed that the billet reaches the desired liquid fraction even by uncertain absolute value of the temperature and by small variations of the alloy composition. For the experiments the steel alloy X210 has been used and measurement data demonstrate the feasibility of the proposed control scheme.

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Biryukov, A. B., and А. А. Ivanova. "Modern status and ways of development of round billet production technology by steel continuous casting." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 76, no. 6 (July 21, 2020): 573–85. http://dx.doi.org/10.32339/0135-5910-2020-6-573-585.

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Production of round billets by steel continuous casting, widely used for manufacturing seamless pipes, railway wheels and tyres, quality long rolled products etc., is widely spread in the world steel industry. Constant search for improved design of CCM takes place, separate parts of existing machines are being perfected. An analysis of collected in the world practice experience of solving problems, related to production of round continuously casted billets, enables to choose proper technical solutions for each particular situation, to determine rational parameters of technology. History of development of round continuously casted billets production technology considered. Data on their modern producers presented. Peculiarities of steel continuous casting technology, as well as reasons of defects of round continuously casted billets have been discussed. Classification of basic kinds of cracks of round continuously casted billet presented. Basic problems during production of round continuously casted billets relate to ovality formation, mainly because of unevenness of heat-away in the mold. The increased ovality can lead to formation of internal and external cracks. Ways of solving problems of defects formation and ways of round continuously casted billet technology perfection summarized. Application of methods of mathematical simulation for a technology, which enables to produce defectless billets considered. It was shown, that basic measures to decrease number of billet defects, relate to setting rational parameters of temperature-speed mode, transfer to internal mold profile, corresponding to the billet shrinkage. Another measure is elimination of uneven impact of the liquid metal stream on the solidifying shell in the area of small and big radius. A perspective direction of round continuously casted billets production technology perfection is application of soft reduction methods and electromagnetic stirring of the liquid metal.

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Maeno, Tomoyoshi, Kenichiro Mori, Yuichi Yanagiya, and Shoma Nishino. "Forging of Parts Having Strength Distribution Using Tailor Friction-Welded Billets Composed of Steel Bars Having Different Quenchabilities." Key Engineering Materials 622-623 (September 2014): 186–93. http://dx.doi.org/10.4028/www.scientific.net/kem.622-623.186.

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Parts having a strength distribution were produced from tailor friction-welded billets consisting of steel bars having different quenchabilities. Chrome steel SCr420 and mild steel S25C bars having high and low quenchabilities, respectively, were joined by friction welding. The tailor friction-welded billets were forged, and then quenched so as to have a strength distribution. The cold formability of the tailored billet was first examined from simple compression in the normal and tangential directions to the joint. No cracks appeared even for an 80% reduction in height in the compression. In a tensile test of the 80% reduced billet, the softer S25C side was fractured and the interface was not fractured. The tailor billets have enough cold formability. The thermal influence around the joint of the tailor friction-welded billets was eliminated by annealing, and thus inhomogeneous deformation around the joint in forging was prevented. A shaft having a high strength flange and a connecting rod having high strength and machinability were produced by forging and quenching of the tailored billet.

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Ponzoa Casado, José Manuel, and Pedro Reinares Lara. "Los programas de fidelización como plataforma de venta directa: clasificación de los titulares según la redención de billetes aéreos." Cuadernos de Gestión 10, no. 3 (2010): 197–213. http://dx.doi.org/10.5295/cdg.100206jp.

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Liang, Xiao Kang, Da Quan Li, Pascal Côté, Stephen P. Midson, and Qiang Zhu. "Comparison of Microstructure and Mechanical Properties of Semi-Solid Castings Produced Using Billets Made by EMS and SEED." Solid State Phenomena 217-218 (September 2014): 332–39. http://dx.doi.org/10.4028/www.scientific.net/ssp.217-218.332.

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The spheroidal grains in billets used for semi-solid casting are generally manufactured by electromagnetic stirring (EMS) during the casting process. This method however, is not economically applicable for small quantities of the thixo billets. Swirled Enthalpy Equilibration Device (SEED) has been developed as a rheocasting process, and the SEED process is of interest for developing new thixo alloys, as well as for optimizing the thixocasting processes for high quality components. The objective of this paper is to compare the microstructure and mechanical properties of aluminum alloy 319s billets and castings produced using EMS and SEED feed materials. The experimental results show that for as-cast billets made from SEED process, a well-developed spheroidal grain structure is distributed throughout the cross-section of the billet, while for as-cast EMS billets, the grain structure is inhomogeneous, i.e., a dendritic structure was present adjacent to the surface of the billet, while a uniform, spheroidal structure was present at the centre. After the thixocasting process, however, the both SEED and EMS billets have well-developed, spheroidal grain structures. Mechanical properties of thixocast and T61 heat treated components are comparable for the both SEED and EMS billets.

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LUKIN, SERGEY V., NIKOLAY I. SHESTAKOV, MICHAIL V. PAVLOV, KONSTANTIN YU LEVASHEV, and ALEKSEY A. ZBRODOV. "MATHEMATICAL MODELING AND OPTIMIZATION OF HEAT PROCESSING OF SQUARE CROSS SECTION STEEL BAR ON THE TECHNOLOGICAL LINE “CONTINUOUS CASTING MACHINE - TUNNEL THERMOS - HEATING FURNACE”." Cherepovets State University Bulletin 1, no. 100 (2021): 41–55. http://dx.doi.org/10.23859/1994-0637-2021-1-100-3.

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The PAO Severstal continuous casting machine (CCM) casts square section 100´100 and 150´150 mm billets that after the gas cutting have average temperature 1000-1100 °С. Then billets CCM, transported to the section mill shop, should be placed into a tunnel thermos for preserving their sensible heat and temperature leveling along their section. In this case hot billets are loadedin the heating furnaces, and heating of the billets to required temperature before rolling can be accelerated several times, increasing capacity of the heating furnace and diminishing the specific fuel consumption. The authors present the mathematical model that allows evaluating the heat state of a square section billet on the technological line “CCM - thermos - heating furnace”. The results of numerical simulation of the billet heat state at optimal modes of heat treatment in the thermos and the heating furnace are given.

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Peng, Zun, Wen Hao Hu, Yan Ping Bao, Min Wang, Li Qiang Zhang, and Chao Jie Zhang. "Research and Application of Dynamic Secondary Cooling Control System for a Continuous Steel Billet Caster." Advanced Materials Research 572 (October 2012): 404–9. http://dx.doi.org/10.4028/www.scientific.net/amr.572.404.

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A two-dimensional heat-transfer model for transient simulation of a billets caster is presented. Its accuracy is verified through measured billet temperature and shell thickness. Billets temperature and solidification are computed by this model as a function of time varying casting speed, secondary cooling water flow rates and temperature, billet cross section, steel grade, and pouring and ambient temperatures. A control methodology and algorithm suitable for online control of 5 strands billet continuous casting machine is integrated in this model. The ability of this model to control the surface temperature profile is demonstrated through dynamic and precise adjustment of secondary cooling water flow rates. This secondary cooling system has been applied to a billet caster in Hangzhou Steel Corporation.

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Gerasimenko, V. G., and L. S. Molchanov. "Directions of development of production of small- size billets for long products." Fundamental and applied problems of ferrous metallurgy, no. 32 (2018): 259–74. http://dx.doi.org/10.52150/2522-9117-2018-32-259-274.

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The aim of the work is to study the technological features of the transfer of metallurgical enterprises to the production of small-size and wire metal products from continuously cast billets. The main parameters of the rolling technology are considered: the size of the billet, the choice of the location of the continuous casting machine, the transfer scheme of continuously cast billets to small- size and wire mills. It is shown that when using a continuously cast square billet with a size of 130x130 mm and 150x150 mm, direct combination of a continuous casting machine with a rolling mill is almost impossible due to the difference in the speed of continuous casting and the roughing group of the mill. The performed calculations show that the scheme of cutting the billets and combining with the intermediate furnace is technologically feasible, however, further heating of the billets leads to significant energy losses. It has been established that an effective option for combining the continuous casting machine with a rolling mill is to use a complex of equipment with a furnace-thermostat for a billets 120 m long. This flowchart reduces the energy consumption for heating the billets by at least 53%. The proposed technology of combining the continuous casting machine with a rolling mill will provide metal savings by reducing the thickness of the scale to 0.4-0.73 mm (an average of 1.1% of the mass of the billet), improve its quality by reducing the depth of the decarburized layer from 1.1 mm to 0.3 mm. The technology provides for the transportation of liquid steel in the ladle from the steel-smelting shop, casting on the continuous casting machine, identification of defects in the billets in a hot condition, supply of the billets with a temperature of 8500С to high-temperature furnaces for heating and subsequent rolling.

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de Lorca, Pedro Tedde. "Los negocios de Cabarrús con la Real Hacienda (1780–1783)." Revista de Historia Económica / Journal of Iberian and Latin American Economic History 5, no. 3 (December 1987): 527–51. http://dx.doi.org/10.1017/s0212610900015342.

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Francisco Cabarrús, banquero madrileño de origen francés, vinculado financieramente a un activo grupo de comerciantes y cambistas también franceses—con enclaves en París y Cádiz—, además de a otras casas españolas, y relacionado política e intelectualmente con la minoría ilustrada, en los últimos años del decenio de 1770 y primeros del siguiente, fue el principal responsable de la emisión de vales reales, peculiar modalidad de deuda pública que llevaba incorporadas características de papel moneda. Como Hamilton ha revelado, ése es el primer ensayo de circulación de dinero en billetes en España. El presente artículo se dirige a demostrar que la emisión de vales reales se inscribe en un conjunto de operaciones crediticias que Cabarrús desarrolló para auxiliar a la Real Hacienda en los años en que España intervino en la guerra de independencia de los Estados Unidos. También se intentan explicar las circunstancias de estas emisiones, las reacciones que suscitaron, los efectos económicos que produjeron, así como el beneficio derivado de todo ello para la economía particular del propio banquero.

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Simachev, A. S., T. N. Oskolkova, A. A. Umanskii, and A. V. Golovatenko. "Non-metallic inclusions in different zones of crystallization of E90KhAF rail steel." Izvestiya. Ferrous Metallurgy 64, no. 2 (April 2, 2021): 135–42. http://dx.doi.org/10.17073/0368-0797-2021-2-135-142.

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Metallographic and X-ray studies of continuously cast billets of E90KhAF rail steel have been carried out. We have established the regularities of non-metallic inclusions distribution over the crystallization zones before and after billets deformation. It was revealed that in crustal zone the main non-metallic inclusions are point oxides, aluminum nitrides, iron silicates (FeO·SiO2) and alumosilicates (Al2O3·SiO2). They were identified in the zone of columnar crystals. In central zone of the billet, manganese sulfides (MnS), manganese silicates (MnO·SiO2), alumosilicates (Al2O3·SiO2), iron silicates (FeO·SiO2), and point oxides were found. It has been determined that concentration and size of nonmetallic inclusions tend to increase from the surface to central zone of continuously cast billets, which is consistent with generally accepted ideas about mechanisms of billet formation during crystallization. The mechanism of deformation of two-phase silicate non-metallic inclusions and their influence on quality of rail products was disclosed. It is shown that inhomogeneous deformability of complex silicate inclusions aggravates their harmful effect on rail products quality. In this case, additional stresses appear in addition to inclusion-matrix deformation and contact stresses existing at interphase boundaries. This pattern also holds for non-deformed silicate inclusions. Such a distribution of inclusions in the billets volume somewhat reduces their negative effect on rails quality, since near-contact layers of the billet undergo more intense deformation during rolling, and as the axial zone of a billet is approached, deformation rate decreases.

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Aceña, Pablo Martín. "Teresa Tortella: Los primeros billetes españoles: las «Cédulas» del Banco de San Carlos (1782–1829), Madrid, Banco de España, 1997." Revista de Historia Económica / Journal of Iberian and Latin American Economic History 17, no. 2 (September 1999): 494–96. http://dx.doi.org/10.1017/s0212610900007898.

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Seo, P. K., Byung Min Kim, and Chung Gil Kang. "Development of Horizontal Reheating System for Semi-Solid Die Casting and Its Microstructure Evaluation." Materials Science Forum 475-479 (January 2005): 377–80. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.377.

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The parts manufactured by die casting process usually contain liquid segregation and porosities. To solve these problems, the semi-solid forming process has been applied. The process enables material in the semi-solid state to be completely filled, and parts with the complicated shape to be fabricated by applying relatively low pressure. This process is necessary in order to control the microstructure of the billet as well as to achieve the desired semi-solid billet state. In this study, a horizontal high-frequency induction heating device which can be fabricated by semi-solid forming irrespective of a billet's size was developed. A globular structure of the reheated billet and a billet's temperature distribution during the reheating process for A356 were investigated.

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Lee, Jong Sup, Yong Bae Kim, Geun An Lee, Dong Su Bae, Jun Pyo Park, and Sang Mok Lee. "A Study on Hydrostatic Extrusion of Al Duo-Casted Billet." Advanced Materials Research 630 (December 2012): 18–22. http://dx.doi.org/10.4028/www.scientific.net/amr.630.18.

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In this study, a Hydro Co-Extrusion Process of Al-Mn/Al-Si hybrid alloys prepared by electromagnetic duo-casting was investigated. Sleeve of the duo-casted billets is 3003 Al-Mn alloy and core is 4004 Al-Si alloy. It is expected hydrostatic stress during the HCE process enhances formability of materials and minimize any defects in extruded billets due to different material properties between two Al alloys. The duo-casted billet was extruded at temperature of 423K and with extrusion ratio of 5. Finally, the effect of the HCE on microstructure of the billet was investigated by an optical microscope.

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Khoroshylov, Oleg, Valentyna Kuryliak, and Oleg Podoliak. "Stages of technological improvement of the process of continuous casting of iron-carbon and copper billets." History of science and technology 10, no. 2 (December 12, 2020): 217–49. http://dx.doi.org/10.32703/2415-7422-2020-10-2-217-249.

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In the article there are presented the stages of improvement of the process of continuous casting. It is revealed, that at the each stage of technological improvement of the process of continuous casting, the damage parameters of billets were reduced. Improvement of the process of continuous casting leads to the improvement of the mechanical properties of the billets and the performance of continuous casting machines. The first stage is shown as the process of transition of the number of experimental developments into quality, during which the casting of billets passed from an unstable process to a stable one. The second stage is characterized by the creation of new improved continuous casting processes. So, besides the existing machines of the vertical type, radial, curvilinear and horizontal casting machines were invented. By the end of the twentieth century, this technological process reached the limit of the possibilities for increasing the quality of performs, and the productivity of continuous casting machines. It is shown that the third stage is intended for continuous casting of copper alloys and is based on the influence of the frequency of the movement of the billets and the reverse movement of the perform during overcoming the static friction force. It was determined that for the frequency of movement of billets made of copper alloys, which are in the range of 2.5...7.5 min-1, the direction of its movement during overcoming the static friction affects the mechanical properties of the billet. The fourth stage - causes an increase in the mechanical properties of the billet due to the use of inertia forces in the alternating movement of the billet. It was revealed that at the fourth stage the mechanical properties of the billets increased most effectively, and the linear performance increased from 0.4...0.8 to 2.5...4.0 m/min, and in some cases to 5.0...7.0 m/min.

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Zuo, Yu Bo, Zhi Hao Zhao, Qing Feng Zhu, Xiang Jie Wang, and Jian Zhong Cui. "Preparing Large Sized Billet of High Strength Aluminum Alloy with the Application of Low Frequency Electromagnetic Field." Advanced Materials Research 472-475 (February 2012): 723–26. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.723.

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Grain refinement is quite important for producing 7050 alloy billet especially in large scale. Low frequency electromagnetic casting (LFEC) process was used to make 7050 aluminum alloy Φ500 mm billets and study the effect of electromagnetic field on the microstructure. The sound Φ500 mm billets of 7050 alloys without any grain refiner can be successfully prepared by the LFEC process. The results show that low frequency electromagnetic field has a significant grain refining effect on 7050 alloy and can effectively eliminate feather grain structure. The microstructures of LFEC ingot from the border to the center of the cross section are all equiaxed grains and are finer and more uniform than that of conventional direct chill (DC) cast billets. The LFEC process also shows a strong power to eliminate hot tearing during casting large sized billet of high strength aluminium alloy.

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Li, Yongbo, Xiandong Yin, Weiling Liu, Yafeng Liu, Weihan Gou, and Kuan Cheng. "Cold Centering Algorithm on Pipe Based on Laser Measurement." Journal of Advanced Computational Intelligence and Intelligent Informatics 21, no. 3 (May 19, 2017): 397–402. http://dx.doi.org/10.20965/jaciii.2017.p0397.

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In view of the present pipe cold-centering processing system, the present situation of the low degree of automation and the deviation from the center position, this research intends to design a kind of tube billet cold-centering processing system based on laser measurement. The system adopts a movable, high-precision laser displacement sensor to the tubular billet’s outer contour, scanning to get the billet cylindrical contour coordinates, and uses the nonlinear numerical filtering least-square-circle fitting method to get the tube billet’s center coordinates. The research results show that the system has a high degree of integrated automation, and the measuring error is less than 0.1 mm when the transition is made to automation. At present, this system has been successfully applied to production, and it successfully realizes tube billet cold centering online processing.

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42

Vargas Zamora, José. "La fuente y el girasol: 150 años de historia." Revista Herencia 31, no. 2 (December 24, 2018): 187–212. http://dx.doi.org/10.15517/h.v31i2.35771.

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El 25 de octubre de 1868 fue inaugurada la primera cañería de la ciudad de San José. La tubería culminaba en la Plaza Principal de la ciudad, en donde el agua emanaba de la fuente de Cupido y el Cisne. La fuente, la tubería y la valla para la Plaza fueron importadas desde Inglaterra. En este escrito hacemos uso de imágenes en billetes, monedas y medallas, para ilustrar los eventos relacionados con dicha fuente, especialmente el impacto de la exportación del café a Europa y su influencia en el modo de vida de los ciudadanos de mediados del siglo XIX. La fuente fue el punto de referencia para el pueblo y para los estudiantes de la cercana Universidad de Santo Tomás, fundada en 1844. En 1944 la fuente fue trasladada a la primera sede la Universidad de Costa Rica fundada en 1940. Años después la fuente fue reparada e instalada en el campus central de la Universidad, donde hoy es un símbolo institucional. Este escrito es parte de la celebración del 150 aniversario de la llegada a Costa Rica de Cupido y el Cisne.

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Jeon, Jae Yeol, Ryo Matsumoto, and Hiroshi Utsunomiya. "Feasibility Study on Die Quenching of AA2024 Aluminum Alloy Billet Using Servo Press." Advanced Materials Research 922 (May 2014): 286–91. http://dx.doi.org/10.4028/www.scientific.net/amr.922.286.

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Die quenching of an AA2024 aluminum alloy billet was carried out using a servo press with ram motion control of WC-20mass%Co dies directly after solution heat treatment (SHT). The cylindrical billets were heated in an electric furnace and transferred to the press, then subjected to uniaxial compression with a reduction in height (Δh/h0) of 2%, 5% or 10% after SHT at 773 K or 823 K. The die quenching was successfully carried out without the precipitation hardening only on the billet after SHT at 823 K by sandwiching for 8 s. The subsequent artificial aging behavior at 463 K in an oil bath was investigated. It is found that the precipitation kinetics is accelerated in the die-quenched billets after SHT at 823 K. The peak hardness of the billet processed with 5% after SHT at 823 K is as high as that of the water-quenched billet, HV 149.0.

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Korsakov, A. A., D. V. Mikhalkin, N. A. Zavartsev, A. V. Krasikov, I. N. Tyshchuk, A. G. Ul’yanov, and V. V. Baikov. "Elaboration of a mathematical model and a computer program for calculation of energy-power parameters of reduction process of continuously casted billets at three-roll screw mills." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, no. 1 (January 19, 2021): 55–62. http://dx.doi.org/10.32339/0135-5910-2021-1-55-62.

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For production seamless hot-rolled pipes, round continuously casted billets (CCB) are used, the diameter of which is restricted by the limit sizes of CCM moulds. The expansion of billets assortment necessary to provide pipe-rolling lines (PRL) by required diameters is possible through preliminary reduction of CCB, which is made mainly at three-roll screw-rolling mills having powerful drives. If a plant has no such mills, billets reduction can be accomplished at existing three-roll Assel’s mills being comprised by various PRLs. However, the possibilities of such mills are restricted by acceptable current loads for their drives, since they are designed to roll out pierced pipe stock, but not to reduce solid billet. To determine energy-power parameters of the process of pipe billet reduction at three-roll Assel’s mills, a mathematical model was elaborated accounting geometric, temperature, kinematic and deformation peculiarities by determination the volume of accumulated metal at each roll before rolling out, section of forming diameter of reduced pipe billet and temperature variation during the reduction. As a result, the software product “Reduction Motor Load 2020” (RML2020) was elaborated, which includes a computing kernel based on the elaborated mathematical model for determining the power parameters of the reduction process and a module for analyzing the initial data with a system of boundary conditions. The interface of the software product allows displaying the results of calculations and analysis both in numerical form and in the form of graphs. The elaborated software product contains a database of the main steel grades and allows calculating the current loads on the Assel’s mill drives during the reduction of billets made of various steel grades. The software allows also to accomplish analysis of the acceptable values of various initial parameters (diameters of the initial and reduced billets, temperature of the initial billet, feed angle and rotation frequency of rolls) to ensure the operation of the mills in the acceptable range of current loads. There is also a possibility of making a report in the form of an Excel document and collecting statistical data on the actual values of current loads. By application the RML2020 program, acceptable reduction modes of a pipe billet made of 15Х13Н2 steel (AISI 414) with a diameter of 156 mm into a billet with a diameter of 120 mm were calculated for screw Assel’s mills of PTL-1 of JSC VTZ.

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Ibhadode, A. O. A., and T. A. Dean. "The Effect of Billet Location on Completely Closed Cavity Die Forging." Proceedings of the Institution of Mechanical Engineers, Part B: Management and engineering manufacture 202, no. 4 (November 1988): 227–35. http://dx.doi.org/10.1243/pime_proc_1988_202_072_02.

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The effect of the accuracy of location of cylindrical billets in completely closed cavity dies, on forging loads and product accuracy has been investigated. Aluminium billets with various off-centre locations were forged at room temperature on a 3000 kN hydraulic testing machine. The results indicate that inaccuracies in billet location significantly affect forging load requirements and dimensional accuracy of forgings. An energy method solution is presented to provide accurate load predictions for relatively small off-centre locations of billets.

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Zhang, Zhi Jian, and Joong Kuen Park. "On the Tensile Stress and Damage Accumulation during Equal Channel Angular Extrusion." Advanced Materials Research 295-297 (July 2011): 2283–89. http://dx.doi.org/10.4028/www.scientific.net/amr.295-297.2283.

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The Cockcroft-Latham (CL) damage factor has been calculated, using FEM simulation, during equal channel angular extrusion (ECAE) of strain hardening materials. A high CL damage factor was predicted inside the billet and the damage was increased with the increasing strain hardening coefficient. This was closely related to a generation of increasingly high tensile stress in the deformation zone inside the billet due to an inhomogeneous deformation. The possibility of cracking inside the ECAE billets was confirmed in the ECAE processing of Ti-0.34O-0.95Fe and Ti-0.5Fe billets. The simulation further predicted that CL damage factor can be reduced by applying back pressure or friction force.

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Lezhnev, S. N., A. B. Naizabekov, E. A. Panin, and A. O. Tolkushkin. "Development and Research of Pressing Technology of Billets in New Design of Equal Channel Step Matrix." Advanced Materials Research 1095 (March 2015): 722–26. http://dx.doi.org/10.4028/www.scientific.net/amr.1095.722.

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Performed a simulation of pressing process of the billet in new designed equal channel step matrix. Made a comparison of the deformation loads and distribution of accumulated strain in the billets, deformed in the proposed and previously known tools. Also investigated forming of the front end of the billets to determine the degree of sharpening of the end sections. Studied the influence of multi-cycle deformation process of billets in equal channel step matrix of a new design on the microstructure and mechanical properties.

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Qiu, Yang, Zhi Feng Zhang, Hao Dong Zhao, Bao Li, and Chun Sheng Chen. "Effect of UDC Casting on Hot Deformation Behavior and Properties of 2A14 Aluminum Alloy." Materials Science Forum 944 (January 2019): 46–51. http://dx.doi.org/10.4028/www.scientific.net/msf.944.46.

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Uniform direct chill (UDC) casting is coupled annular electromagnetic stirring and intercooling, having been utilized for the preparation of large-sized aluminum alloy billet. In this paper, the UDC casting was applied to 2A14 aluminum alloy billets with a diameter of 584 mm. Hot compression tests, cogging and ring rolling procedures were carried out for the billets, respectively. The results show that during the deformation temperature of 420 °C and the strain rate of 0.01 s−1 to 10 s−1, the flow stresses of different positions are higher and more stable in the UDC casting billet than in the normal direct chill (NDC) casting billet. The dislocation glide is the dominant deformation mechanism of 2A14 aluminum alloy. Meanwhile, the UDC casting significantly improves the mechanical properties of the rolled rings in tangential and axial directions compared with the NDC casting.

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Qu, Fu, and Jian Zhong Cui. "Effects of Electromagnetic Field and Lubricate Condition on the Surface Quality of Aluminum Alloy Billet during LFEC Processing." Applied Mechanics and Materials 268-270 (December 2012): 378–81. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.378.

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The microstructures of the aluminum billets could be improved markedly by low-frequency electro-magnetic casting (LFEC) processing. In fact, the low-frequency electromagnetic field (LFEF) also has favorite effect on the surface quality of billet. However, few public reports on the surface quality of LFEC aluminum billets could be found. Therefore, a new crystallizer together with a kind of lubricant was designed aiming at lowing surface turning quantity, and the effects of casting velocity, electromagnetic condition and lubrication on the surface quality of aluminum billets were investigated. The results indicate that LFEF together with the lubricate condition would be responsible for the surface quality of the billets, and the high surface quality billets could be achieved by optimizing the casting conditions.

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Akhtar, S. S., Abul Fazal M. Arif, and A. K. Sheikh. "Influence of Billet Quality on Hot Extrusion Die Life and its Relationship with Process Parameters." Advanced Materials Research 83-86 (December 2009): 866–73. http://dx.doi.org/10.4028/www.scientific.net/amr.83-86.866.

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Apart from other factors such as die design and manufacturing, heat treatment, working conditions etc, performance of hot extrusion die can directly be related to the billet quality used in the extrusion press. The purpose of this paper is to investigate the effect of Al-6063 billet source (primary or secondary) on extrusion die life based on microstructural and statistical analyses. In microstructural investigation, secondary (remelt) billet cast in-house at local extrusion plant is compared with primary (smelter) billet by applying different material characterization techniques including optical microscopy, hardness measurement, X-ray diffraction (XRD) analysis, and energy dispersive spectroscopy (EDS). The statistical study is based on the failure history of some 53 hollow-profile dies in which the effect of billet quality on various measurable process parameters including extrusion ratio, billet temperature, exit temperature and repeated nitriding is analysed and related with useful die service life. Comparatively coarse grain structure, non-homogeneous distribution of secondary phases, and high hardness in the case of secondary billet were found responsible for poor die performance as observed in statistical investigation of failed dies. Two types of regression models are also proposed for prediction of die life in terms of secondary billets’ usage and measurable influencing parameters. Using current results, some suggestions during in-house billet preparation of secondary billets have been devised for improved die life.

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Journal articles on the topic 'Billetes'

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