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By Márcio Corrêa de Carvalho

Welded deposited chromium carbide overlay’s has been widely used in various branches of welding overlay’s industry related to wear. Characterization techniques are an important tool in the development of chromium carbide overlays resistant to wear, enabling the identification of phases, constituents and defects. In this work one used optical microscopy, scanning electron microscopy and energy dispersive spectroscopy on chromium carbide overlay’s deposited by submerged arc welding process. The characterization techniques identified precisely the elements of the overlay’s enabling point of the main cause of the observed defects such as cracks, porosity and clusters of particles known in the industry as " rice crispy" .

Aug 16, 2017

By Carlos Alberto Mourão, Robson Martins, Letícia Madureira Moreira, Hélio Braz Loss, Joilson Moreira Ferreira da Silva, Edilson Simões Cavalieri, Mauricio Ferreira Coelho

O conversor AOD-L é de uso exclusivo para a produção de aços inoxidáveis na Aperam South America. Entre janeiro a julho de 2018, o consumo de FeSi estava acima do orçado, acarretando em perda de gestão para a Aciaria. O aço inoxidável AISI 304 representa 50% da produção da Aciaria na rota duplex (sem uso do VOD), portanto, esse projeto teve como objetivo a redução do consumo da liga de FeSi no AOD-L para o aço AISI 304. Essa redução foi possível através da utilização da metodologia Lean Six Sigma na qual a causa raiz foi identificada e as ações implementadas o que permitiu uma maior estabilidade operacional, além de aumentar a competitividade da Aperam South America frente aos demais produtores mundiais.

Oct 1, 2019

By Lucas Silva Fontes

Este estudo trata da metodologia de projeto de tratamento térmico para pinos J. O pino J funciona como fusível mecânico do obturador de produção de petróleo e deve romper numa determinada faixa de carga de cisalhamento, a fim de que não haja excesso de tração no obturador. Foram feitas análise química, análise da intensidade de tensões devida à forma do pino, ensaios de dureza e ensaios de cisalhamento. O estudo foi eficiente para determinar o adequado tratamento térmico a fim de garantir a tensão de cisalhamento estipulada no projeto do pino.

Aug 16, 2017

By Zhi Zhang

The ever increasing demand of high performance rolls in the late finishing stands (F5 – F7) for hot strip mills (HSM) requires better product solutions from roll suppliers. Roll development activities never stop at Union Electric Åkers (UEÅ) in order to meet the requirement. The HYBRID STEEL, a new concept of roll materials especially for the late finishing stands in the HSM, is successfully developed in UEÅ. This paper reviewed the development of previous ICDP as well as enhanced ICDP (eICDP) roll materials, and, the novel HYBRID STEEL roll grade. Rolls manufactured by this new grade have been used in several European mills. A significant improvement over the enhanced ICDP rolls has been observed.

Oct 30, 2017

By Luiz Alberto dos Santos

. In this work, samples of the alloy with composition of 50.9 % at. Ni were machined and were subjected to hot tensile test, after the machining all the samples were solubilized so that all were in the same condition during the hot tensile test. The hot tensile tests were performed between the temperatures 350-650°C and the yield stress were between 800 and 597.1 MPa and area reduction between 17 and 75% with respect to the initial area. The test at 350°C shows a fragile fracture characteristic while the hot tensile test above this temperature showed a predominantly ductile fracture. The fragile fracture is evidenced by the river marks that are characteristic of this type of fracture, because in this condition does not promote much plastic deformation. The higher temperatures present ductile fracture, because present the dimples that also characterize this type of fracture. This work shows the temperature relationship in the mechanical properties, more specifically the hot tensile test, in the NiTi alloy.

Oct 30, 2017

By Jorge Madias

Pin holes as a surface defect, and blow holes as an inner defect, occur in billet / bloom / beam blank casting, particularly for Si-Mn killed steel cast with metering nozzle and oil lubrication. If they are present in abundance or have a large size, they may originate defects in the rolled products. Their characteristics, factors behind their formation, as well as usual processing conditions that promote their occurrence are discussed. Finally, the evolution of these defects during reheating and rolling is analyzed, with industrial examples.

Aug 16, 2017

By Diogo de Oliveira Costa, Eduardo de Amorim Braga de Oliveira, Alan José Santos De Almeida, Deilton de Oliveira Sousa, Luciano Machado de Oliveira

A Ternium Brasil, localizada no Rio de Janeiro, possui dois Altos Fornos. Ambos iniciaram operação em 2010, Alto Forno 01 em 13/07/2010 e Alto Forno 02 em 06/12/2010. A GAD é uma unidade de processo que tem a finalidade de receber, classificar, dosar o carvão bruto, realizar sua moagem e secagem para o processo de injeção de carvão pulverizado em Alto Forno à coke. O trabalho apresenta o processo de melhoria, os recursos de gestão aplicados, a perspectiva a curto e longo prazo e o resultado alcançado até o momento.

Oct 1, 2019

By Guilherme Vitor de Araujo, Igor Cuzzuol dos Santos, Loyslene Rabelo Fernandes, Gustavo Henrique Sousa, Athos Fernandes Araujo

O desenvolvimento de nanopartículas magnéticas vem recebendo bastante atenção de pesquisadores devido a sua potencial aplicação em diferentes campos tecnológicos, principalmente em microeletrônica e medicina. A magnetita nanoparticulada é particularmente atraente para estas finalidades, pois apresenta comportamento superparamagnético, biocompatibilidade e resistencia à oxidação. Neste estudo foi avaliado a síntese das nanopartículas pela coprecipitação. Para isso foi observado a influência da razão molar de Fe+2/Fe+3 e da variação de concentração de NaOH na nucleação e precipitação das partículas. Sendo possível, determinar os melhores parâmetros para obtenção das mesmas e garantindo as suas propriedades. Para a constatação estrutural, a caracterização das amostras foi realizada por difração de raios X (DRX). A razão molar de Fe+2/Fe+3 se mostrou uma variável importante, em razões muito pequenas o resultado obtido foi goetita, enquanto a síntese a partir da razão 0,5 observou-se apenas a magnetita. E a variação da concentração de OH- teve influência no tamanho das partículas nucleadas, no qual menores partículas foram obtidas em meios mais básicos.

Oct 6, 2019

By Manoel Inácio dos Reis Neto

Redução no consumo específico (KW/t) de energia elétrica em um dos moinhos de bauxita na refinaria da Alumina na CBA (Companhia Brasileira de Alumínio do grupo Votorantim Metais) através do uso da Metodologia Six Sigma e ações de substituição do óleo mineral por óleo sintético de alta performance, implantação do sistema de blindagem e de resfriamento no redutor deste moinho, onde foi alcançado um resultado de 5,45% de redução neste consumo específico e de 25% na temperatura de trabalho deste redutor, superando as expectativas inicias previstas.

Jul 31, 2018

By Jorge Madias

La mayor parte de las máquinas de colada continua de palanquillas que utilizan buzas calibradas y lubricación con aceite se operan con alta velocidad de colada en secuencias largas, obteniendo alta productividad. Muchos de ellos todavía practican la inyección de aluminio en el molde, para desoxidar el acero líquido sin riesgo de obturación de las buzas. También es todavía usual la práctica de “pescar” la nata que se forma en el menisco. Las salpicaduras del chorro de cuchara contribuyen a la formación de chanchos en el repartidor, requiriendo el lanceo con oxígeno. Alternativamente, diversas plantas prefieren utilizar tubo de protección entre cuchara y repartidor y protección con gas inerte del chorro del repartidor al molde en todos los grados de acero colados con buza calibrada. Se hace una comparación entre ambas prácticas desde los puntos de vista de inversión, costo operativo, seguridad, productividad y calidad.

Jul 30, 2018

By Erich Bartel

The Kocks Rotation Mill - KRM- is an innovative elongation method for seamless tube production up to 4.5’’ diameter at production levels up to150,000 TPY. Using the principle of cross roll elongation, the machine rotates four rolls around the workpiece. A retained mandrel sets the wall thickness to a precision that exceeds existing industry norms. The KRM process performance has been truly excellent. Attributes include high billet weights, elongation of up to 9.5 in one pass, and eccentricity at or below +/- 5.0%. The flexibility of the process allows a wide range of steel grades to be produced at any wall thickness with little or no mill down time. Surface quality and yield are also greatly improved. Based upon the small foot print of the KRM rotor as well as the simple mandrel manipulation system, the installation cost of the KRM is significantly lower compared to other elongation methods. The reasonable cost of the machine, combined with greatly reduced foundation requirements, reduced ceiling height as well as simple utility connections reduce the initial investment for a new or upgraded mill. Finally, lower roll and mandrel costs allow high quality production at greatly reduces cost/ton.

Aug 16, 2017

By John Anthony Vasquez

During the last years Riva Acciaio Verona has taken the decision to invest in the route of a fully automated meltshop. The aim is to reduce at the minimum the operator's intervention from the bucket preparation till the ladle transfer to the continuous casting bay. The foundation for achieving the goal is the introduction of innovative technological solutions (fully automated cranes for bucket charge in the EAF, robots for sampling, etc. The paper underlines how the different solutions are based on the best practices to improve operator's safety and describes the different steps of the project, the different solutions adopted and the results in terms of production, energy savings, cost reduction and improved safety. Details are presented for: scrap yard management and bucket preparation, EAFs centralized controls and related robots for auxiliary operations (sampling, EBT cleaning, scraper for slag door automation, complete mass & energy balance based on process control), LFs centralized controls and process integration.

Aug 16, 2017

By Anna Carolina Cerqueira Neves

Synthetic fiber has been gradually replaced by natural fiber, such as lignocellulosic fiber. In comparison with synthetic fiber, natural fiber has shown economic and environmental advantages. The natural fiber presents interfacial characteristics with polymeric matrices that favor a high impact energy absorption by the composite structure. However, until now little has been evaluated about the hemp fiber incorporated in polymeric matrices. This study has the purpose of evaluate the impact resistance of this kind of epoxy matrix composite reinforced with different percentages of hemp fibers. The impact resistance has substantially increased the relative amount of hemp fiber incorporated as reinforcement in the composite. This performance was associated with the difficulty of rupture imposed by the fibers resulting from the interaction of hemp fiber / epoxy matrix that helps absorb the impact energy.

Aug 16, 2017

By Michaela Böberl

State of the art sinter coolers are working based on the cross flow cooling principle. Thus, only a part of the thermal energy can be used for heat recovery application. The other part of the cooling air is brought unused to the environment. Furthermore, environmental regulation regarding dust emission and intelligent usage of exergy are getting stronger. Therefore, Primetals Technologies developed sinter coolers based on the counter flow principle. The cooling air passes the sinter bed in counter-flow direction enabling a direct heat transfer from the hot sinter to the air. The exhaust gas temperature can be maximized by using the total heat of the hot sinter. Due to the possible usage of the total exhaust gas amount, diffusive dust emission is reduced to zero. Two types of counter flow coolers are in the portfolio of Primetals Technologies. One type is based on a stationary shaft, in which the hot sinter is charged. The flow of the hot sinter is in vertical direction from top to bottom, in counter direction than the cooling air. The second type is a circular hopper cooler. The hot sinter is charged on top of a moving bed. At the bottom of the bed the sinter is discharged. The cooling air flows also from the bottom to the top, following the counter flow principle. Depending on the requirements, one of the two counter flow cooler types can be chosen for optimized and efficient cooling of hot sinter..

Oct 30, 2017

By Delio Amorim

Industry 4.0 concepts is the new biggest challenge on the industry nowadays and every company in every industry in every part of the globe is looking to implement this somehow on their factories and machines. To do that on the newest long rolling mills, that brings already onboard state-of-the-art technologies, is for sure a challenge of machinery builder industry, but how to become the long rolling mills built on 70’s, 80’s or 90’s part of this innovation process and connected to the new trends? This is the main mission here, to show some examples of applications that goes in this direction.

Oct 1, 2019

By Eltton de Sousa Veras

Entendendo-se a complexidade e o impacto da etapa de Perfuração e Desmonte de Rochas nos processos unitários subsequentes, foi iniciado um projeto para otimização do planejamento e execução desse processo. Dessa forma, foi desenvolvido um projeto para auxiliar no planejamento e execução das malhas de perfuração utilizando o sistema High Precision Drill System (HP-DS). Foi realizado um levantamento em campo para comprovação dos ganhos potenciais de redução de custo e aumento de produtividade, sendo resultados expressivos do ponto de vista financeiro, operacional e de segurança, possibilitando uma redução potencial de 15,8% (percentual de metragem que não agrega valor) de metros perfurados sem comprometer o grau de fragmentação especificado para as operações unitárias de lavra. A eliminação dessas perdas representaria uma redução potencial de custos na ordem de 20 milhões de reais.

Oct 30, 2017

By Markus Reifferscheid

Industry 4.0, Digitalization, Internet of Things (IoT) and Cloud Computing are predominant topics in the world economy at the moment. At the ABM week 2017 Dr. Markus Reifferscheid, Head of Research & Development of SMS-group, will talk about the proceeding digitalization in the steel industry with selected examples of SMS-group. He will present advanced concepts and solutions which are currently being developed.

Oct 30, 2017

By Igor Barros Mairinck

Este trabalho consiste num estudo investigativo, no campo teórico, visando levantar informações de processo, modelagem e simulações do sistema de controle da linha de Preparação de Bobinas 1 (PB1), processo em batelada de corte e bobinamento de aços inoxidáveis da APERAM. A partir deste modelo simulado, foi realizada avaliação de desempenho e sugeridas alterações do controle e novos parâmetros do controlador de bobinamento, de forma a contribuir para a melhora do desempenho das malhas de controle e do processo real. Foram analisadas as interações entre os componentes do circuito de controle e os impactos no desempenho global do sistema no domínio do tempo e da frequência. Este conhecimento adquirido propiciou sugestões de melhoria do comportamento do sistema.

Aug 16, 2017

By Walmir Pereira de Amorim Junior

Imersas em um mercado em constante mudança, as empresas têm seguido em uma busca contínua pela melhoria de seus processos. Diante disso, nos últimos 2 anos, o segmento de Aços Planos da ArcelorMittal Brasil vem passando por um processo de transformação, revisitando e reestruturando seus processos internos. Na área de planejamento um dos itens avaliados foi o processo de Planejamento de Vendas e Operações – Sales and Operations Planning (S&OP). O objetivo desse trabalho é a apresentação do novo modelo de S&OP da ArcelorMittal Brasil – Aços Planos, seus benefícios, e ferramentas utilizadas para suportar essa evolução: o SAP Integrated Business Planning for S&OP e a plataforma de colaboração SAP Jam, responsável por orquestrar todo fluxo de S&OP e as interações entre as diversas áreas envolvidas. O novo processo foi baseado nos conceitos existentes na literatura e também é objeto desse artigo. Além disso, no projeto de implementação do SAP IBP e SAP Jam foram utilizadas a Metodologia de Gerenciamento de Projetos baseada nas melhores práticas descritas pelo PMBOK (Project Management Body of Knowledge) do PMI (Project Management Institute) e a Metodologia SAP Activate para a implementação dos produtos. Como resultado da implantação desse projeto, foram obtidos vários benefícios, sendo alguns deles já atingidos e outros a serem capturados após o período de adaptação e estabilização dos processos e ferramentas.

Oct 30, 2017

By Jens Kempken

A competitive landscape pressurizes the steel producers business, zero defect requirements from customers forces the operators for additional efforts in process control and quality management. The so called quality related cost, which include also rework, cost for downgrading or even scabbing of material is already a remarkable lever in a plants profitability breakdown. The introduction of advanced state of the art grades in the product portfolio requires already a budgeting for the expenses for R&D and quality management. PQA has been developed as a process and quality management software solution next to existing level 2 or level 3 automation systems. It is focusing on the analysis of process data, equipment information, in line quality measurement devices and trend analysis to obtain an answer whether the process is according to definition and expectation and whether the intermediate or final product can be shipped for further processing as prime material. Advanced analytics which are linked to an expert know how based configuration identifies deficiencies in the production and processing process. An intelligent, state of the art quality rating system evaluates tolerable deviations. PQA comprises the software platform including the database, data configurator and collector from the different sources in the production process and units. The core element of the platform is the knowledge based expert know how package defining process and quality determining fundamentals. The paper describes the structure of the software package, it gives insights on the expert know how package, process and quality evaluation and points out the customer benefits, cost reduction, improvement yield, customer satisfaction increase. The link to recent operational references is given.

Oct 30, 2017