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By Eric Yoshimitsu Sako

One of the main difficulties in the operation of trough and runners at Arcelor Mittal Tubarão (AMT) Blast-furnace no.02 is the reduced amount of time available for repair procedures. The consequence is that the castable installation must often be performed during hot conditions and the installed castable could easily detach from the base material during the early stage of operation, exposing the previously oxidized base material to molten iron and corrosive slag attack. When events like this happen, emergency repairs must be executed, resulting in increased refractory unit consumption and an unplanned shutdown of unit operation. Considering these targets, Nippon Crucible Co. and Saint-Gobain HPR Brazil have developed a high-performance Al2O3-SiC-C composition based on an entirely novel anti-oxidation technology. Oxidizing reactions could be attenuated by adding an oxidant inhibitor and a water reducing agent. As a result, the open porosity was significantly reduced, resulting in an improvement of campaign life in terms of pig iron throughput when compared with the regular castable. An analysis of this life improvement showed successful results for the material after 250 days of campaign. The main reason for such successful results was that the deterioration caused by the oxidation was significantly less and that this change made on the high cohesive structure of the base material was maintained for a long time. The attained results allowed Arcelor Mittal Tubarão to achieve longer trough campaigns, and avoid any unplanned stoppages with zero breakdown risks.

Oct 30, 2017

By Diego Pacheco Wermuth

Micrometric surgical components typically have high geometric complexity and stringent regulatory specifications. These components need to have excellent mechanical properties and a high demand of products. Besides these factors, it is necessary to maintain a low manufacturing cost, performing essential research on new manufacturing technologies. Metal Injection Molding (MIM) is a process that has been explored , providing an interesting alternative for making medical devices. The research in the production of microcomponents obtained for MIM is gaining momentum and prominence, due to low cost and high productivity of this process. This paper is a study and development of feedstocks with AISI 316L alloy , which is known for its biocompatibility. Four feedstocks with 61%vol. of metal powder were analyzed by capillary rheometry and DSC/TGA.

Aug 16, 2017

By Olivier Lacroix, Dubé Mathieu, Guylaine Laforest

The reduction behavior of iron ore pellets in gas-based DR shaft processes has been studied at COREM since the late 80s. At that time, a new DR characterization test called COREM R180 was developped in collaboration with ArcelorMittal Mines Canada (former Quebec Cartier Mining) and ArcelorMittal Long Products Canada (former ISPAT Sidbec Inc.). This paper describes COREM’s approach to improve its understanding of the relations between iron ore pellet microstructure and pellet quality. The differences between the DR90 and the R180 tests are discussed. The evolution of the microstructure during reduction of both tests is also described. The reduction steps during the two tests are put forward as an important factor impacting the microstructural changes as well as the test results.

Oct 1, 2019

By Danilo Gonçalves de Oliveira, Rogério Martins Pereira

Chatter is a widely studied vibration phenomenon that affects most cold mills around the world and its impact on these lines are tremendous: from productivity and quality losses to mechanical equipment damage. The investigation of its origins and how to minimize the occurrences and their impact on the equipment require special instrumentation and algorithms in order to have a detection of the vibrations as soon as they start. This paper presents three methods of identification of chatter on a Tandem Cold Mill and the actions to leave the vibration frequency range before its amplitude achieve catastrophic values.

Oct 1, 2019

By Jose Maria Rodriguez-Ibabe, Ronaldo Antonio Neves Marques Barbosa, Douglas Glenn Stalheim

Major costs in the production of both flat and long commodity grade structural steel products include alloy, labor and energy. Flat and long commodity grade structural steels such as ASTM A36, ASTM A527Gr50, S235, S275, S355 and other equivalent world societal standards represent over 500 million annual tons worldwide. These simple commodity grades consist of a minimum of three base common alloying elements, carbon, manganese, silicon and then can be supplemented with microalloying elements of either vanadium or niobium. Since 2016 raw material costs for two of the five alloying elements in these commodity grade structural steels, FeMn and FeV, have risen significantly and/or have become volatile making it difficult to maintain stability in profitability for these commodity grades. For steel plants producing hundreds of thousands and in some cases over a million tons annually of these common structural steel grades because of the significant alloy cost increase for Mn and V alloy additions has squeezed profitability of these grades. These grades typically represent the base loading for cost controls in most all steel plants and hence a significant cost increase or volatility in two of the five elements used for these grades having a negative effect on overall production costs. However, with a proper strategy for alloy designs working in conjunction with the mills existing processing capabilities to achieve the desired end metallurgy/mechanical properties, alloy costs and operational efficiencies can be realized.

Oct 1, 2019

By Chad B. Donovan

There is a strong need in North America and other major steel producing markets where major capital investment in new equipment has been minimal over the past several years to make improvements to existing casting machines. In many cases, very cost effective improvements can be made to existing equipment in order to maximize the efficiency and production of an older designed continuous caster, a classic caster. SMS Group and its predecessor companies have been maintaining continuous casting molds for over forty years. This experience has allowed SMS Group to intimately understand the advantages and disadvantages of each design. The most vital component of the continuous caster is the mold copper design, as it has the most influence over the ability to cast a quality product. Updating to a modern copper design is less complicated than most steel producers think and the benefits are significant. Premium mold coatings such as UniGuard® and NanoGuard® allow casters to guard against exposed copper and wear while producing quality products for record campaign lengths.

Oct 30, 2017

By Chad Byron Donovan

There is a strong need in North America and other major steel producing markets where major capital investment in new equipment has been minimal over the past several years to make improvements to existing casting machines. In many cases, very cost effective improvements can be made to existing equipment in order to maximize the efficiency and production of an older designed continuous caster, a classic caster. SMS Group and its predecessor companies have been maintaining continuous casting molds for over forty years. This experience has allowed SMS Group to intimately understand the advantages and disadvantages of each design. The most vital component of the continuous caster is the mold copper design, as it has the most influence over the ability to cast a quality product. Updating to a modern copper design is less complicated than most steel producers think and the benefits are significant. Premium mold coatings such as UniGuard® and NanoGuard® allow casters to guard against exposed copper and wear while producing quality products for record campaign lengths.

Aug 16, 2017

By Anna Carolina Cerqueira Neves

Synthetic fibers have been gradually replaced by lignocellulosic fibers. Compared to the synthetic fiber, natural fiber showed economic and environmental advantages presenting interfacial characteristics with polymer matrices that favor the impact energy absorption by the composite structure. However, so far little has been reported about the hemp fiber embedded in polymer matrices, such as tensile properties. This study aims to evaluate the resistance in tensile tests of epoxies composites reinforced with different percentages of hemp fiber. Tensile tests were submitted with percentage of 0%, 10%, 20% and 30% incorporated hemp fiber in epoxy matrix. The tensile strength and deformation substantially increased the relative amount of hemp fibers incorporated into the polymeric matrix.

Aug 16, 2017

By Dong Maolin

A great amount of high temperature off-gas, whose maximum temperature is up to 2100?, is generated during the smelting process of electric arc furnace (EAF). The dust content, which is mainly iron oxide, of the off-gas is high and worthy of industrial recovery. The heat carried by the high temperature off-gas with dust is about 11% of the total energy input of EAF, and some even is as high as 20%. The high-temperature off-gas not only takes away a lot of heat but also places a huge burden to de-dusting system of EAF. It not only reduces the iron oxide dust recovery ratio, but also causes serious pollution problems. With the development of the iron and steel industry, the proportion of molten iron for EAF gradually increases, and even more than 30% in some cases. The increase of molten iron causes increases in the amount of EAF off-gas and heat waste. As a result the problem of dust removal is worsening [1-2]. How to sufficiently recover the sensible heat of the high temperature off-gas, create conditions for efficient dust removal, thus reduce operating costs of dust removal system and the production costs is a problem which EAF steel making companies must pay attention to.

Oct 30, 2017

By Aperam South America

Balanço Energético Global e Utilidades - 2013

Jul 31, 2018

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 Gabriel Andrade Medeiros, Christian Brugger, Paul Pennerstorfer, Daniel Fuchshuber, Reinhold Leitnerl

State-of-the-art automation technology enables digitalization of the continuous casting process that goes far beyond conventional automation of industrial production. Primetals Technologies provides a digital twin that combines an intelligent digital representation of a casting machine as well as the casting process and the slabs, blooms or billets that are produced. It allows metallurgists and process engineers to predict the behavior of the involved complex production process and optimize parameters before using them in real production. New steel grades or production processes can be evaluated off-line without any risks to process stability and product quality. Primetals Technologies installs the digital twin with every new installation of a continuous caster optimization system. This paper describes how the setup and simulation possibilities of the digital twin provide numerous benefits by modelling and simulating the casting process. It allows for example the calculation of material properties according to the actual composition, strand surface temperature profiles and dynamic soft reduction before the final point of solidification. An outstanding feature of the digital twin is the replay functionality provided for various models to analyze and further optimize real production situations. The paper also gives an example how usage of the digital twin optimized production at a customer.

Oct 1, 2019

By Dyego Monteiro de Souza

This study compares the wear resistance of specimens lubricated with biofluids or mineral oil. Tribological studies were performed by ball-cratering test. In these tests were used as lubricants epoxidized soybean oil, castor oil and mineral oil. The specimens used were untreated and nitrided AISI 4140, while a steel ball AISI 52100 was used as a counterbody. In order to analyze the results obtained, the worn volume was calculated and the characterization of the crater, after the test, was made using optical microscopy and SEM. Wettability was also measured for the different surface condition and lubricants. As expected both specimens showed a smaller volume worn when lubricated with mineral oil due to inherent properties of this type of lubricant. Among the vegetable oils studied, the castor oil showed a better performance in the lubrication of the specimens untreated while on the nitrided specimen have shown less wear when lubricated with epoxidized soybean oil, indicating a difference in the efficiency of oils, as lubricants, depending on the surface conditions of the mechanical components.

Jul 31, 2018

By Tiago Salzmann Vilela

No mercado de arames galvanizados destinados a indústria é exigida a uniformidade da camada de zinco sobre o arame. Neste trabalho, foram estudados os efeitos da velocidade de galvanização na uniformidade e espessura da camada de Zinco total, bem como a morfologia das fases de Zn e Ferro-Zinco sobre o substrato metálico. Verificou-se também o efeito do aquecimento após o processo de galvanização, observando o crescimento da camada intermetálica. Finalmente, serão mostradas as principais características de processo obtidas para garantir o atendimento aos ensaios de qualificação, em um estudo de caso de arames galvanizados produzidos em unidade industrial da Gerdau.

Jul 30, 2018

By Edgar Ivan Castro Cedeño

En la producción de aceros limpios el control inclusionario es crítico para la obtención de un producto que cumpla con los requerimientos de calidad. El análisis de la distribución de tamaño de inclusión mediante modelos estadísticos permite estimar la incidencia de inclusiones en el producto solidificado a partir de mediciones tomadas en muestras relativamente pequeñas. En seis coladas de acero bajo carbono desoxidado con aluminio se tomaron muestras de acero a lo largo del procesamiento en horno olla y colada continua. Las muestras se prepararon para estimar mediante análisis metalográfico los tamaños de inclusión. Los datos de tamaño de inclusión se analizaron mediante modelos estadísticos de valores extremos, se hace una comparativa entre la distribución Gumbel (que forma parte de la norma ASTM E-2283) y la distribución Generalizada de Valores Extremos (GEV). Mediante una prueba de hipótesis con el estadístico Anderson-Darling, análisis de cuantiles y con la función de supervivencia se demuestra que la población inclusionaria se describe de una mejor manera con la distribución GEV. Finalmente se da un estimado de la incidencia probable de inclusiones en el producto solidificado.

Aug 16, 2017

By Renata Cristina Teixeira

The lubricant oil is a complex mixture of different basestocks and additives. Engine oils evolved from the use of pure mineral basestocks back in the early years of automotive industry to the advent of synthetic, fully formulated, low ash lubricants. This evolution was driven by a number of factors, such as new engine designs, extended durability needs, increased fuel economy needs, environmental concerns, feedstock prices and availability and legal issues. This paper uses technology prospecting on literature and patents databases to allow an investigation on the historical evolution of engine oils. Main basestocks (mineral, hydrotreated, polyalphaolefins, esters) and additives (antioxidants, antiwear, friction modifiers, detergents and dispersants) are characterized according to their research effort. Technology prospecting data is crosschecked against the evolution of engine oil classes, allowing an analysis of how the main drivers push the development of lubricant oil quality. A research effort was identified in late 1990’s until mid-2000’s and related to the adoption of chemical limits for lubricants. Different patterns for the articles and patents publication account for the high value technological knowledge has in this industry. Technology prospecting is seen as a useful methodology for the understanding and forecast of lubricant technology movements.

Jul 31, 2018

By Rafael Abreu Fraga, Carlos Noberto Paula da Silva, Emanuelle Garcia Reis, Daniel Bojikian Matsubara

Since 2016 Gerdau Ouro Branco has been producing steel plates of various qualities and grades. However, it was not until 2018 that the first plates produced by accelerated cooling process were made available for external testing, in this case for large diameter UOE pipes manufacturing. Recent line pipe and OCTG specifications are showing that the oil and gas market still consumes regular API grades, such as X60, X65 and X70, however with increasing wall thicknesses, reaching values up to 1.5 inches. These specifications also demand longitudinal and transverse tensile guarantees and drop weight tear tests in temperatures as low as -40°C. Projects with these types of mechanical properties present process requirements as challenging as those necessary for higher API grades in lower thicknesses. This paper shows the steel design concepts and rolling routes for achieving the necessary properties for X70 steel plates in 28.15 mm. The microstructural features were also investigated and associated with the production process and the tensile and toughness results. Finally, challenges such as tensile anisotropy and DWTT abnormal fracture are presented.

Oct 1, 2019

By "Andreas Steinwandter

The demand for increasing energy efficiency and CO2 reduction is one of the global megatrends of our time. Although the steel industry suffers from a volatile economic environment, the steel plants are interested to find opportunities for sustainable cost reduction and put efforts into healthy solutions for the environmental. Integrated steel plants are trying to cut electrical power and energy costs as these are among the biggest cost factors that can be influenced and taking all the advantages they can. For the integrated iron and steel making route the interaction of waste energy utilization along with process energy demand, natural and metallurgical gases, steam and heating systems as well as power generation has to be considered. Potential energy sources, such as sinter plant, basic oxygen furnace (BOF) cooling stack or reheating furnaces are considered in order to elaborate an integrated energy concept. Especially electric power generation is an attractive option for steel plant operators since it can easily be connected to the existing power grid of the steel plant. When direct local use of waste heat is limited, the best option is to convert it to mechanical/electrical power with a Rankine Cycle. A stand-alone system, compact design with minimum operational costs in order to fit into the existing steel plant layout, are the main requirements of such units. The objective of this paper is to demonstrate economic feasible opportunities for energy recovery for sinter cooler and basic oxygen furnace with focus on electric power generation via ORC modules taking at the same time advantages of CO2 reduction by utilizing waste heat from the process. Furthermore typical arrangements and layouts of such solutions as well as basic economic calculations will be presented in the paper.

Oct 30, 2017

By Mery-Cecilia Gómez-Marroquín

O presente trabalho trata da formação da ferrita de zinco a partir da mistura e posterior reação solido-solido entre o óxido de zinco e óxido de ferro - Fe2O3 puros em proporções equimolares. A faixa de temperatura onde teve lugar a formação foi entre 1073 e 1373 K. Testes de redução da ferrita da zinco sintética-ZF e pós de aciaria elétrica–EAFD foram realizadas usando misturas de CO e CO2 que variaram entre 50 e 100% CO. Ambos os testes (formação e redução de ZF e EAFD) foram suportados usando técnicas de caracterização física, química, estrutural e microscópica. No caso da redução, foi observado que tanto a temperatura como a percentagem de CO, foram os fatores que, mais afetarem a redução de ferrita de zinco contida no EAFD. A máxima percentagem de redução da ZF foi 85%, para 100% CO, 1373K e 105 min, e 52%, para 50% CO, 1373K e 105 min. Por outro lado, atingiu o 100% para 100% CO, 1273K, em 80.75 min, 60%, para 50% CO a 1373K durante 105 min. no caso da redução do EAFD

Aug 17, 2017

By Ron Webber

With the difficult economic challenges currently facing the steel industry, it is essential to perform a complete analysis when determining which rolls to purchase. A properly designed “Total Cost of Ownership” model can result in significant savings. This paper will review the costs associated with rolls in both Hot Strip and Cold Strip Mills. The multitude of factors that must be considered in performing a complete analysis for the roll purchasing process will be discussed. Models for both Hot Strip and Cold Mills will be presented. Examples where traditional analysis can lead to expensive, incorrect decisions will be presented.

Oct 30, 2017