ABSTRACT Introduction: in Cuba, in 2018, a total of 12 070 new cases of skin cancer were diagnosed, from which it is estimated that 11 587 correspond to the non-melanoma type. Radiation therapy with X-rays is considered the first-line treatment in many of these cases. Recently, the national healthcare system acquired four SENSUS SRT-100TM units for treating Non-Melanoma Skin Cancer (NMSC). Objective: to develop a standardized methodology for the dosimetric characterization of the equipments of surface radiotherapy with X-rays installed in Cuba. Methods: four SENSUS SRT-100TM radiotherapy equipments were characterized for each of their radiological qualities, in terms of linearity, stability, hemi-reductive layer, reference dose rates, dose profiles, cone factors and percentage of dose in depth. The recommendations of the AAPM TG-61 and the IAEA-TRS 398 were applied for this purpose. Results: the averages of HVLs (mm Al) and their respective coefficients of variation (CV) were 5,526 - 5,2 %; 1,130 - 2,1 % and 2,007 - 2,1 % for 50, 70 and 100 kV respectively. The yields presented little variability between machines (CV < 3%) and were very similar by the methods "in water" and "in air" (discrepancy < 0,5 %). Conclusions: the equipments show excellent stability and very similar dosimetric characteristics among them, which allows establishing reference values for eventual external audits and beam readjustments after the maintenance or repairs involving the X-ray generator.

RESUMEN Introducción: en Cuba, en el 2018, fueron diagnosticados un total de 12 070 nuevos casos de cáncer de piel, de los cuales se estima que 11 587 corresponden a la variante no melanómica. La radioterapia con rayos x está considerada como la primera opción de tratamiento en muchos de estos casos. Recientemente, el sistema nacional de salud, adquirió cuatro equipos de la marca SENSUS SRT-100TM para el tratamiento del NMSC. Objetivo: desarrollar una metodología estandarizada para la caracterización dosimétrica de los equipos de radioterapia superficial con rayos X instalados en Cuba. Métodos: se caracterizaron cuatro equipos de radioterapia SENSUS SRT-100TM para cada una de sus calidades radiológicas, en términos de linealidad, estabilidad, capa hemirreductora, tasas de dosis de referencia, perfiles de dosis, factores de cono y porcentaje de dosis en profundidad. Se emplearon para ello, las recomendaciones de la AAPM TG-61 y el IAEA-TRS 398. Resultados: lo promedios de las HVLs (mm Al) y sus respectivos coeficientes de variación (CV) fueron de 5,526 - 5,2 %; 1,130 - 2,1 % y 2,007 - 2,1 % para 50,70 y 100 kV respectivamente. Los rendimientos presentaron poca variabilidad entre máquinas (CV < 3%) y fueron muy similares por los métodos “en agua” y “en aire” (discrepancia. < 0,5 %). Conclusiones: los equipos muestran una excelente estabilidad, y características dosimétricas muy similares entre ellos, lo cual permite establecer valores de referencia para eventuales auditorías externas y re-ajustes de los haces ulteriormente a los mantenimientos o reparaciones que impliquen al generador de rayos X.

Resumo Satisfação no trabalho é uma variável psicológica que vem sendo estudada na ciência organizacional contemporânea por sua relação com uma série de variáveis como performance, turnover, comprometimento organizacional e resiliência. Um problema encontrado na literatura científica é a ausência de uniformidade no uso de medidas que quantifiquem a satisfação laboral. Com o objetivo de identificar o estado da arte de instrumentos que avaliem a satisfação no trabalho no mundo, na América Latina e no Brasil, uma revisão sistemática nas bases Web of Knowledge, Scopus e SciELO foi conduzida. Os resultados geraram um montante de 357 artigos que, após aplicados critérios de exclusão, foram reduzidos a 154. Ao todo foram encontradas 62 escalas diferentes usadas em 42 países distintos em todo mundo. Em relação aos resultados globais, duas escalas foram identificadas como as mais utilizadas nos estudos internacionais, bem como em relação aos estudos realizados na América Latina. Já no Brasil, apenas uma escala pode ser considerada.

Abstract Job satisfaction is a psychological variable that has been studied in contemporary organizational science due to its relation with a series of variables such as performance, turnover, organizational commitment and resilience. One problem found in the scientific literature is the lack of uniformity regarding the use of measures of job satisfaction. In order to identify the state of the art of instruments that evaluate work satisfaction worldwide, in Latin America and in Brazil, a systematic review on the Web of Knowledge, Scopus and SciELO bases has been conducted. The search generated a list of 357 articles that, after applying exclusion criteria, were reduced to 154. Altogether 62 different scales were found in 42 different countries around the world. Regarding the overall results, two scales were identified as the most used in the international studies, as well as in relation to the studies carried out in Latin America. In Brazil, only one scale could be considered.

Resumen La satisfacción laboral es una dimensión psicológica que se ha estudiado en ciencias de la organización contemporánea gracias a su relación con: el rendimiento, el turnover, el compromiso organizacional y capacidad de recuperación. Un problema encontrado en la literatura científica es la falta de uniformidad en el uso de medidas que cuantifican satisfacción en el trabajo. Con la intención de identificar el estado de las herramientas de evaluación de la satisfacción en el trabajo en el mundo, en América Latina y Brasil, una revisión sistemática en las bases Web of Knowledge, Scopus y SciELO se llevó a cabo. Los resultados generaron un total de 357 artículos que después de aplicar los criterios de exclusión, se redujeron a 154. En total, se encontraron 62 diferentes escalas utilizadas en 42 países diferentes en todo el mundo. A respecto a los resultados generales, dos escalas fueron elegidos como la relación más utilizados, así como en América Latina. En Brasil, sólo una escala puede ser considerada.

ABSTRACT Purpose Overactive Bladder (OAB) is a clinical condition characterized by symptoms reported by patients. Therefore, measurement instruments based on reported information are important for understanding its impact and treatment benefits. The aim of this study was to translate, culturally adapt and validate the Urgency Questionnaire (UQ) in Portuguese. Materials and Methods Initially, the UQ was translated and culturally adapted to Portuguese. Sixty-three volunteers were enrolled in the study and were interviewed for responding the Portuguese version of the UQ and the validated Portuguese version of the Overactive Bladder Questionnaire short-form (OABq-SF), used as the gold standard measurement for the validation process. Psychometric properties such as criterion validity, stability, and reliability were tested. Results Forty-six subjects were included in the symptomatic group (presence of “urgency”), and seventeen were included in the asymptomatic group (control group). There was difference between symptomatic and asymptomatic subjects on all of the subscales (p≤0.001). The UQ subscales correlated with the OABq-SF subscales (p≤0.01), except the subscale “time to control urgency” and the item “impact” from the visual analog scales (VAS). However, these scales correlated with the OABq-SF - Symptom Bother Scale. The UQ subscales demonstrated stability over time (p<0.05), but the subscale “fear of incontinence” and the item “severity” of the VAS did not. All of the UQ subscales showed internal consistencies that were considered to be good or excellent. Conclusion The Portuguese version of the UQ proved to be a valid tool for the evaluation of OAB in individuals whose native language is Portuguese.

Abstract The coolant delivery technique known as Minimal Quantity Lubrication (MQL) has been employed in machining since the end of the 20th Century and has gained considerable evidence in the last years as a viable alternative to the use of the conventional coolant technique (flood). Due to the low oil flow rate delivered by the MQL technique in grinding operations, that generally varies from 20 to 240 ml / h in relation to near 600,000 ml / h flow rate of the conventional coolant technique, the MQL technique provides a reduced risk for human health and environmental damage associated with the use, maintenance and disposal of cutting fluids. In this context, this study was carried out to evaluate the application viability of the minimum quantity lubrication coolant technique under different flow rates in the plunge cylindrical grinding of ABNT 4340 steel with an aluminum oxide wheel. Three flow rates were tested: 30, 60 and 120 ml/h. Grinding trials with the conventional coolant delivery method were also tested for comparative purposes. The output variables used to assess the efficiency of the MQL technique in this work are: roughness, roundness and hardness of the workpiece. Grinding wheel wear and power consumption were also monitored. The results showed that, despite the higher values of roughness and roundness of the workpiece, as well as the grinding wheel wear, the values of these same parameters obtained after machining with the MQL technique were close to those obtained after machining with the conventional technique. No thermal damages and cracks on the machined surface, or even below the machined surface, were observed after grinding ABNT 4340 steel irrespective of the coolant-lubrication condition investigated. The results showed that the MQL with 120 ml/h can be an alternative coolant technique due to cleaner environment and lower consumption of fluid in grinding under the conditions investigated in this work.

A retificação é um processo de usinagem preciso, sendo uma das etapas mais caras na fabricação dos moldes para injeção de termoplásticos. Na retificação o rebolo é a ferramenta abrasiva responsável pela retirada do material. O número de tipos de abrasivos e granulometrias disponíveis são bastante grandes e junto com a quantidade de ligas possíveis, estruturas e durezas, além dos formatos, fazem com que se chegue a um número enorme de produtos. O conhecimento das suas características técnicas, vantagens, defeitos e condições de trabalho são fundamentais para os engenheiros de produto, de processos e, naturalmente, para os gerentes de área industrial, identificarem qual o rebolo mais indicado para realização do processo de retificação. Dentre os aços utilizados na fabricação de moldes para injeção de termoplásticos destaca-se o aço VP-50, o qual foi o aço usado neste experimento, sendo usinado pelo processo de retificação cilíndrica. No processo de retificação, também foi adotado para fins de experimento dois métodos de lubrirrefrigeração, sendo eles o método convencional com lubrirrefrigeração abundante e o MQL que é a técnica com mínima quantidade de lubrirrefrigeração. O objetivo deste trabalho foi analisar de forma comparativa o desempenho de corte executado com três tipos de rebolos convencionais: rebolo de óxido de alumínio branco, rebolo de carbureto de silício verde e rebolo de carbureto de silício preto com óxido de alumínio branco. Os resultados foram analisados e comparados pelas variáveis de saída dos três tipos de rebolos, tipo de refrigeração e espessura equivalente de corte.

The grinding is a precise machining process, one of the most expensive steps in the manufacture of in-jection molds for thermoplastic. In grinding the grinding wheel abrasive tool is responsible for removal. The number and types of abrasive grit sizes available are quite large and together with the number of possible alloys, structures and shapes of hardness beyond cause reach an enormous number of products. The knowledge of their technical characteristics, advantages, defects and working conditions are fundamental for product engineers, process and of course to the industrial area managers, which identify the most suitable grinding wheel to perform the grinding process. Among the steels used in the manufacture of molds for ther-moplastic injection highlight the VP-50 steel, which was the steel used in this experiment being machined by the cylindrical grinding process. In the grinding process was also adopted for the purpose of experiment two methods of lubrication and cooling them with the conventional method with abundant lubrication and cooling and MQL is the technique with minimal amount of lubrication and cooling. The objective of this study was to analyze comparatively cutting performance, performed with three types of conventional wheels: grinding of white aluminum oxide, green silicon carbide grinding wheel and grinding of black silicon carbide with white aluminum oxide. The results were analyzed and compared by the output variables of the three types of wheels, type of refrigeration and equivalent thickness.

ABSTRACT The aim of this study was to assess social and intimate relationships of elderly individuals with Hansen’s disease. This study has a quantitative approach, with 60 elderly individuals from two Hansen’s Disease Control Programs in the capital city of a Brazilian Northeastern state, using the Social Relationships domain of the World Health Organization Quality of Life – bref and the Intimacy facet of the World Health Organization Quality of Life – older adults, with descriptive statistical analysis. Data were collected between December 2012 and June 2013. In the Social Relationships domain, satisfaction was found at 85% in personal relationships, 78.3% in social support and 60% in sexual activity. The elderly individuals presented lower satisfaction in the Intimacy facet. The Social Relationships of elderly individuals with Hansen’s disease presented a high score due to the social support network, which presented significant satisfaction and reflected on quality of life. In conclusion, it is important that nursing coordinates strategies for educational and care practices for elderly individuals affected by Hansen’s disease.

RESUMEN El objetivo fue evaluar relaciones sociales así como íntimas de personas ancianas con enfermedad de Hansen. Abordaje cuantitativo, con 60 ancianos en dos Programas de Control de la enfermedad de Hansen, en una capital del nordeste brasileño, utilizando el Dominio de las Relaciones Sociales del World Health Organization Quality of Life – bref y la categoría Intimidad del World Health Organization Quality of Life – older adults, con análisis estadístico descriptivo. Los datos fueron obtenidos entre diciembre de 2012 y junio de 2013. En el Dominio de las Relaciones Sociales, la satisfacción fue de 85% en las relaciones personales, 78,3% en el apoyo social y 60% en actividad sexual. En la categoría Intimidad, los ancianos presentaron menor satisfacción. Las Relaciones Sociales de los ancianos con enfermedad de Hansen presentó alto escore a causa de la red de apoyo social, trayendo expresiva satisfacción y reflejando en su cualidad de vida. Se concluye que es muy importante que la Enfermería articule estrategias de prácticas educativas y de cuidados al anciano con enfermedad de Hansen.

RESUMO Objetivou-se avaliar relações sociais e íntimas de pessoas idosas com hanseníase. Abordagem quantitativa, com 60 idosos em dois Programas de Controle da Hanseníase, em uma capital do nordeste brasileiro, utilizando o Domínio das Relações Sociais do World Health Organization Quality of Life – bref e a faceta Intimidade do World Health Organization Quality of Life – older adults, com análise estatística descritiva. A coleta de dados ocorreu entre dezembro de 2012 e junho de 2013. No Domínio das Relações Sociais, a satisfação foi de 85% nas relações pessoais, 78,3% no suporte social e 60% em atividade sexual. Na Faceta Intimidade, os idosos apresentaram menor satisfação. As Relações Sociais dos idosos com hanseníase apresentou alto escore devido à rede de apoio social, trazendo expressiva satisfação e se refletindo na sua qualidade de vida. Conclui-se sobre a importância da Enfermagem articular estratégias de práticas educativas e de cuidados à pessoa idosa e com hanseníase.

Objective: to assess the chromatographic methods for the chemical stability of a new 2 % miconazol nitrate cream. Methods: various degradation conditions were firstly used in the raw material miconazole nitrate in order to obtain the possible degradation products of this drug and to evaluate them by thin layer chromatography-based method, which was validated to identify the degradation products in the new cream. The performance of the official method based on high resolution liquid chromatography and reported in British Pharmacopeia 2010 was evaluated, and its selectivity against the possible degradation products were also analyzed. Both chromatographic methods were applied to the analysis of cream samples from the three pilot batches under heat stress for 30 days. Results: the two methods showed high selectivity against excipients and degradation products of the drug. Miconazol nitrate was degraded against acid hydrolysis, thermolysis and photolysis, being the detection limit of 1 µg for the thin layer chromatography. No degradation of the analyte was observed in any of the three analyzed batches according to the qualitative and quantitative results. Conclusions: these methods are valid for the submitted objective, so they may be used in the chemical stability study of 2 % miconazol nitrate creams.

Objetivo: evaluar los métodos cromatográficos para la estabilidad química del nitrato de miconazol en una nueva crema al 2 %. Métodos: en primer lugar se aplicaron diferentes condiciones degradativas al nitrato de miconazol materia prima a fin de obtener los posibles productos de degradación del fármaco y evaluarlos por un método diseñado por cromatografía en capa delgada, el cual se validó para identificar productos de degradación en la crema. Se evaluó el desempeño del método oficial informado en la Farmacopea Británica 2010 por cromatografía líquida de alta resolución para la valoración del nitrato de miconazol en la crema, analizando su selectividad frente a los posibles productos de degradación. Ambos métodos cromatográficos fueron aplicados al análisis de muestras de crema procedentes de los tres lotes pilotos sometidos a estrés térmico durante 30 días. Resultados: ambos métodos mostraron elevada selectividad frente a los excipientes y los productos de degradación del fármaco. Se obtuvo degradación del nitrato de miconazol frente a hidrólisis ácida, termólisis y fotólisis y el límite de detección fue de 1 µg para cromatografía en capa delgada. No se mostró degradación del analito según los resultados cualitativos y cuantitativos en ninguno de los tres lotes analizados. Conclusiones: los métodos utilizados son válidos para el objetivo con el cual se proponen, por lo que pueden emplearse en el estudio de estabilidad química de las cremas de nitrato de miconazol al 2 %.

INTRODUÇÃO: A embolização de fragmentos de ateroma/trombo durante a intervenção coronária percutânea (ICP) ocasiona distúrbios de perfusão da microcirculação. O novo stent MGuardTM, que é revestido com uma rede de polietileno, demonstrou eficácia na prevenção de complicações embólicas durante a ICP primária. No entanto, a evolução clínica tardia de pacientes tratados com o stent MGuardTM permanece desconhecida. MÉTODOS: Uma série de 65 pacientes portadores de lesões coronárias de novo tratados com o stent MGuardTM foi analisada. Os dados clínicos basais, do procedimento e do seguimento clínico tardio (média de tempo, 2,6 ± 1,4 anos) foram coletados retrospectivamente por meio da revisão de prontuários médicos e/ou contato telefônico direto. RESULTADOS: A média de idade foi de 66,1 ± 13,7 anos, 32,3% eram diabéticos, 49,2% tinham infarto agudo do miocárdio (IAM) prévio, e 44,6% apresentaram-se com síndrome coronária aguda. Dois terços das lesões estavam localizados em pontes de safena, quase metade tinha presença de trombo e a maioria foi classificada como tipo B2/C. O stent MGuardTM foi implantado com sucesso em todos os casos. Ao final do procedimento, fluxo TIMI 3 foi alcançado em 93,4% e o sucesso angiográfico foi de 91,8%. No seguimento tardio, as taxas de eventos adversos incluíram óbito cardiovascular em 6,2%, IAM não-fatal em 9,2%, revascularização da lesão-alvo em 9,2% e trombose de stent definitiva/provável em 1,5%. CONCLUSÕES: O seguimento tardio de pacientes com lesões coronárias complexas tratados com o stent MGuardTM demonstrou baixas taxas de revascularização da lesão-alvo e de trombose do stent.

BACKGROUND: The embolization of atheroma/thrombus fragments during percutaneous coronary intervention (PCI) causes microcirculatory perfusion disturbances. The new MGuardTM, a mesh-based bare-metal stent, demonstrated efficacy in the prevention of embolic complications during primary PCI. However, the late clinical outcome of patients treated with the MGuardTM stent remains unknown. METHODS: A series of 65 patients with de novo coronary lesions treated with MGuardTM stent was analyzed. Baseline clinical data, procedure and late clinical follow-up (mean duration, 2.6 ± 1.4 years) data were collected retrospectively by a review of medical records and/or direct telephone contact. RESULTS: Mean age was 66.1 ± 13.7 years, 32.3% of patients were diabetic, 49.2% had a previous acute myocardial infarction (AMI), and 44.6% presented with acute coronary syndrome. Two thirds of the lesions were located in a saphenous vein graft, almost half of the lesions had thrombus and most were classified as type B2/C. The MGuardTM stent was successfully implanted in all cases. At the end of the procedure, TIMI 3 flow was achieved in 93.4% and angiographic success was 91.8%. In the late clinical follow-up, adverse event rates included cardiac death in 6.2%, non-fatal AMI in 9.2%, target lesion revascularization in 9.2% and definite/probable stent thrombosis in 1.5%. CONCLUSIONS: The late follow-up of patients with complex coronary lesions treated with the MGuardTM stent demonstrated low rates of target lesion revascularization and stent thrombosis.

INTRODUÇÃO: A via radial evoluiu na última década para uma abordagem versátil, mostrando resultados equivalentes ou superiores aos da via femoral. Avaliamos a incorporação da técnica radial em um centro formador de cardiologistas intervencionistas, e comparamos seus resultados aos da técnica femoral. MÉTODOS: Estudo observacional, unicêntrico, que incluiu pacientes consecutivos submetidos a intervenção coronária percutânea (ICP) entre 2007 e 2011. A via de acesso foi escolhida pelo residente, em conjunto com o intervencionista responsável pela ICP. Comparamos o desfecho combinado de óbito, infarto do miocárdio (IM) periprocedimento, acidente vascular cerebral isquêmico ou sangramentos maiores entre os dois grupos na fase hospitalar. RESULTADOS: Foram submetidos a ICP 5.545 pacientes, 29,8% pela via radial e 70,2% pela via femoral. A média de idade foi de 60,8 ± 11,7 anos, sendo 68,9% do sexo masculino e 29% portadores de síndromes coronárias agudas. Houve aumento do uso da via radial até 2010, e estabilização no ano subsequente (11,8% em 2008, 26,1% em 2009, 45,1% em 2010 e 42,6% em 2011). Os pacientes que utilizaram a via radial tinham perfil tanto clínico como angiográfico menos complexo. Não houve diferenças nos desfechos combinados (5% vs. 5,9%; P = 0,18), no óbito (0,1% vs. 0,8%; P = 0,71), no acidente vascular cerebral (0,06% vs. 0,03%; P = 0,53) ou no IM periprocedimento (4,5% vs. 3,8%; P = 0,27). Contudo, menor incidência de sangramentos maiores (0,4% vs. 1,3%; P < 0,01) e de complicações vasculares (0,5% vs. 2,2%; P < 0,01) foi observada com a via radial. CONCLUSÕES: Em nosso centro formador de cardiologistas intervencionistas, a ICP pela via radial foi rapidamente incorporada, e trouxe, para pacientes selecionados, resultados equivalentes aos da via femoral, com redução dos índices de sangramentos maiores e de complicações vasculares.

BACKGROUND: The radial artery access has evolved into a flexible approach in the last decade, showing similar or superior results when compared to the femoral approach. We assessed the incorporation of the radial artery access in a training center for interventional cardiologists and compared the results to those of the femoral artery access. METHODS: Observational, single-center study, including consecutive patients undergoing percutaneous coronary intervention (PCI) between 2007 and 2011. The access route was chosen by the resident along with the interventionist responsible for PCI. We compared the composite endpoint of death, periprocedural myocardial infarction (MI), ischemic stroke or major bleeding between the two groups during hospitalization. RESULTS: Among 5,545 patients undergoing PCI, 29.8% used the radial approach and 70.2 used the femoral approach. Mean age was 60.8 ± 11.7 years, 68.9% were males and 29% had acute coronary syndromes. There was an increase in the use of the radial approach until 2010 and stabilization in the subsequent year (11.8% in 2008, 26.2% in 2009, 45.1% in 2010 and 42.6% in 2011). Patients using the radial approach had a less complex clinical and angiographic profile. There were no differences in the composite endpoint (5% vs. 5.9%; P = 0.18), death (0.1% vs. 0.8%; P = 0.71), stroke (0.06% vs. 0.03%; P = 0.53) or periprocedural MI (4.5% vs. 3.8%; P = 0.27). However, there was a lower incidence of major bleeding events (0.4% vs. 1.3%; P < 0.01) and vascular complications (0.5% vs. 2.2%; P < 0.01) with the radial approach. CONCLUSIONS: At our interventional cardiology training center, PCI through the radial approach was quickly incorporated and provided, for selected patients, outcomes similar to those of the femoral approach, with decrease of major bleeding and vascular complication rates.

La tecnología de maquinado a alta velocidad (High Speed Machining o HSM) ha permitido el maquinado de aceros en estado endurecido. En este trabajo se comparó experimentalmente el tiempo fabricación de una cavidad de molde de pequeñas dimensiones utilizando la secuencia de procesos convencional que incluye electroerosión y utilizando una secuencia en que se realiza el proceso de fresado en duro con estrategias HSM tanto para desbaste como para acabado. El uso de la secuencia de procesos con maquinado HSM en duro resultó en una reducción de 55% en el tiempo de manufactura comparado con el proceso tradicional usando electroerosión. Sin embargo, es importante anotar que en aplicaciones específicas debe realizarse un análisis de la secuencia de procesos adecuada para cada caso particular considerando los costos y beneficios pues no hay una secuencia que sea mejor en todos los casos.

The high speed machining (HSM) technology has allowed the machining processing of hardened steels. In this paper we compared experimentally the manufacturing time to produce a mould cavity of small dimensions using the conventional process sequence that includes EDM and using a sequence with hard HSM milling strategies for both roughing and finishing. The sequence with hard HSM milling resulted in a reduction of 55% of total manufacturing time compared with the traditional process using EDM. However, it is important to note that for specific applications it should be done an analysis of the appropriate processes sequence for each particular case considering the costs and benefits, because there is no sequence that is best in all situations.

Neste trabalho foram calculados e comparados os custos de soldagem associados a cada um dos ensaios realizados, como forma de determinar parâmetros operacionais adequados e economicamente viáveis para soldagem com o processo MIG/MAG com transferência metálica por curto-circuito, visando uma correta deposição de revestimentos com ligas de níquel sobre um substrato de aço C-Mn. O número de ensaios a serem realizados, foi determinado pelo uso do método Taguchi que dividiu os ensaios em duas matrizes L9, resultando num total de 18 ensaios. Na comparação dos gastos despendidos em cada um dos ensaios foi utilizado o custo direto total da soldagem de um revestimento com 55 mm de largura e 190 mm de comprimento, utilizando uma sobreposição de 50%. Com base nos resultados dos ensaios foram pré-selecionados quatro ensaios (R7, R11, R12 e RC4), dentre os quais o ensaio R11 apresentou o menor custo. Mas vale ressaltar que nos quatro ensaios pré-selecionados o material de adição utilizado foi a liga 625, pois esta liga apresentar um custo do arame-eletrodo muito inferior as demais ligas (C-276 e 686). Assim a escolha do material de adição para aplicação do revestimento ficou restrita somente a liga 625.

In this work were calculated and compared the welding costs for each of the tests performed to determine operational parameters and economically feasible for welding with GMAW process in a short circuiting transfer mode, aiming at a correct weld overlay with nickel alloy on a substrate of C-Mn steel. The number of tests to be performed was determined by using the Taguchi method that divided the tests into two L9 orthogonal arrays resulting in a total of 18 experiments. To compare the costs incurred in each of the tests we used the total direct cost of welding a layer with dimensions of 55 x 190 mm, using an overlap of 50%. Based on the results of the tests were pre-selected four tests (R7, R11, R12 and RC4), among which the test R11 has the lowest cost. But it is noteworthy that the four pre-selected test alloy 625 was used as filler metal, because the electrode wire of this alloy has a much lower cost compared to other alloys (C-276 and 686). Thus the selection of the filler metal for weld overlay was restricted only to alloy 625.

Neste trabalho utilizou-se o método Taguchi (planejamento Robusto de experimentos), para cumprir com um reduzido número de ensaios, dois objetivos: obter a influência dos fatores de controle sobre as variáveis respostas e determinar as condições ideais para aplicação das ligas de níquel nas soldagens de revestimentos através do processo MIG/MAG com transferência metálica por curto-circuito. Foram escolhidos seis fatores de controle com três níveis cada: Tensão de referência, Velocidade de soldagem, Tipo de tecimento, Técnica da tocha, Gás de proteção e o Material de adição. Por sua vez as variáveis respostas escolhidas foram: Diluição (D) e Razão entre o reforço e a largura (R/L). As soldagens foram realizadas na posição plana por simples deposição sobre chapas de aço ASTM 516 Gr60 com dimensões de 200 x 50 x 12,7 mm. O uso do tecimento proporcionou cordões com baixos valores da razão R/L e obteve valores bastante baixos de diluição chegando à ordem de 5%. A combinação dos níveis dos fatores de controle apontados como ótimos pelo método Taguchi resultaram em valores para as variáveis repostas consideradas adequadas para a soldagem de revestimento.

In this work aim the Taguchi method (Robust design of experiments) was chosen to achieve with a limited number of tests two objectives: the first was to the influence of the control factors (welding parameters) on quality characteristics (weld bead geometry) and the second was to determine optimal conditions for weld overlay with nickel alloy through the GMAW process in a short circuiting transfer mode. Six control factors were employed with three levels each: Reference voltage, Welding speed, Arc oscillation, welding gun orientation (Perpendicular, forehand and backhand), Shielding gas and filler metal. Already the employed quality characteristics were: Percent dilution (D) and the ration between reinforcement and bead width (R/L). The weldings were accomplished using a bead on plate (BOP) technique, flat position, in steel ASTM 516 Gr60 with dimensions of 200 x 50 x 12,7 mm. The results showed that the use of arc oscillation promote weld bead with low values of the ratio R/L and obtain low dilution's values arriving to the order of 5%. The combination of levels of control factors identified as optimal by the Taguchi method obtained values for the variables considered suitable for weld overlay.