Search Documents

By Márcio Lobato Genelhu

Este trabalho tem o objetivo de apresentar o modelo de recuperação refratária a quente dos regeneradores dos altos-fornos, através da técnica de solda cerâmica, visando o aumento da vida útil e evitando a parada prematura para a manutenção destes equipamentos. A aplicação da solda cerâmica prolongou a vida útil dos regeneradores.

Aug 8, 2018

By Renan Gurgel Pinho

O objetivo deste trabalho é investigar a esferoidização do aço SAE 1080 e os respectivos efeitos da variação do tempo na microestrutura final e na dureza do material. O aço SAE 1080 foi submetido a recozimento isotérmico, por tempo prolongado, utilizando-se 90, 100 e 120 horas de aquecimento à temperatura de 715ºC. Os resultados mostraram que é possível esferoidizar o aço SAE 1080 nos respectivos tempos escolhidos e perceber aumento da quantidade de esferoiditas, assim como decréscimo na dureza.

Aug 16, 2017

By Carolina Sartori Marzullo

Apresenta-se a metodologia e sistemática para gestão da capacitação como ferramenta para aumento da competitividade e ganho de resultados do negócio num contexto crítico para o segmento.

Aug 16, 2017

By Samuel Vasconcellos

Em plantas de separação do tipo PSA ocorrem oscilações na vazão de ar intrínsecas a este processo, devido à repressurização dos vasos pré-purificadores ser feita em intervalos muito curtos. Por meio da instalação de um buffer tank foi possível tornar a coluna de destilação mais estável, aumentando a produção de líquidos, reduzindo a demanda de energia e otimizando a pré-purificação.

Jul 31, 2018

By Andrea Pezza

The steel market is experiencing a difficult conjuncture: on the one hand steel producers minimize their investments while optimizing their over- production, on the other hand suppliers reduce their internal human resources and capacity in order to overcome the instability of the new era. A return to the steel production levels of the past is not expected in the short term. Research, development and plant concept optimization is one recipe to drive the future of the steel business. This article describes a new concept for a VOD plant developed as a result of thorough investigation and assessment of all possible solutions. A joint and tight cooperation with the final customer was necessary to reaching important results. This article consists of the contributions from the plant suppliers in terms of their experience and feedback, as well as the final user’s. The final customer, voestalpine Giesserei Linz GmbH, and the plant supplier, Primetals Technologies, are both worldwide players and highly focused on reaching best quality and innovation.

Oct 30, 2017

By Antônio Aldenor Pinheiro Neto, Matheus de Lima Vieira

In mid-2015 the steel industry faced a strong crisis due to the weak performance of the Brazilian economy and the persistent entry of Chinese steel into Brazilian territory. This situation demanded that Brazilian steelmakers seek to develop products to meet new export markets. within the volume of exports possible are the rebars, where its applications are in the construction industry. One of the largest importers is Peru which has a large percentage of this export volume. This market demands as a priority requirement the surface quality of blue condition (low oxidation index) and mechanical properties normative.in order to meet the items required by the customer at a competitive cost, a vanadium microalloyed steel was applied to the hot rolling process without heat treatment after the last rolling pass. Where the great challenge was to achieve a high level of stretching without compromising the minimum limits of tensile strength. Assuming that the steel used is the correct one interventions were made on rolling parameters such as set-point temperature, residence time of pieces in the furnace, linear mass and rolling speed. All the changes made were based on statistical tools and practical tests. Finally, with the execution of actions generated from the statistical analyzes and tests it was possible to reduce process losses by 96%.

Oct 1, 2019

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 Carlos Martins de Oliveira

The trucking industry is constantly seeking improvement and cost reduction of their vehicles, studying new lighter and robust materials to meet the needs of its customers. The objective of this work is to study the application of DCPD Telene, PU. R. RIM and PP-TD 20 materials in aesthetic components of trucks: bumper, calender, upper and lower bracket and side air deflector. A multifunctional work team was created to work in such parts of IVECO trucks. The work began with an analysis of possible improvements to the current parts and followed the subsequent phases: definition of new materials, virtual modeling, new tools, and durability test in vehicles. It could then be verified that the proposed DCPD Telene, PUR. RIM and PP-TD 20 materials showed greater strength, better painting surface, and reduced weight and cost in parts.

Aug 8, 2018

By Peter Grawenhof

In steel mills universal joint shafts, slipper spindles and gear spindles are used to overcome the design- and process- related offset between the axis of the motors and the work rolls. At the roll side the available space for the couplings is limited by the minimum work roll diameter. This leads to extremely high loaded components of the universal couplings especially at the roll side joints. Furthermore modern steel mills continuously strive to roll larger plates and materials with increased strength. This requires drive solutions with even higher torque capacity. For these applications conventional design joints are not sufficient anymore. Even alternative solutions such as hybrid- or offset- designs fall short. Therefore the companies Voith and BUMA Engineering developed together the new GearLink drive concept in close cooperation with the Voestalpine Grobblech GmbH. A completely new combination of universal joints and gear couplings offers an up to now unique solution enabling the use of 1,35- times bigger joint with a 2,5- times higher torque capacity and a 20- times longer lifetime. The GearLink system was first time successfully taken into operation at Voestalpine Grobblech in December 2013 and is up to now working without issue.

Aug 16, 2017

By Marcelo Rebellato, Beatriz Pereda, Beatriz Lopez, Pello Uranga

The classical application of Nb microalloying in the development of thermomechanical processes for flat products has been related to its suitability to enhance strain-induced precipitation and get a pancaked austenite prior to transformation. As new steel grades or new lay-outs are being developed, more complex metallurgical conditions need to be evaluated. In this context, Nb microalloying, alone or combined with other microadditions, needs to intervene in a more controlled way in additional steps of the thermomechanical process, besides its conventional strain-induced precipitation role. For example, the hardenability enhancement associated with Nb to properly achieve lower temperature transformation products, demands a proper balance of the Nb amount precipitated during rolling and the one remaining in solid solution. Similar effects are also sought when the final available Nb is used to increase strength through precipitation hardening. This manuscript evaluates how changes in the rolling strategies affect the interaction between Nb(C,N) precipitation and austenite recrystallization at different steps of the rolling process. As the possible interactions between parameters intervening simultaneously are quite complex, the application of microstructural models helps to properly define the best austenite conditioning combined with the convenient amount of Nb in solution, as a function of the final property requirements. Along the manuscript, several strategies will be discussed for the case of hot rolling of flat products comparing both normal and coarse initial austenite grain sizes.

Oct 1, 2019

By Alexander Fleischanderl

Steel market has become somehow unpredictable and requires quick adjustment in production conditions to survive in the harsh market environment. Steel production is not anymore driven by output records, but by efficient cost reduction measures to remain competitive under strongly varying production conditions. Energy efficient production and flexible raw material scenarios have become decisive factors to succeed and survive in our industry. Such scenarios have to be carefully investigated to be well prepared to adopt production steps continuously. The paper analyses various process opportunities to optimize energy and raw material consumption in the production route. Off-gas treatment systems have still a huge untapped potential to recover energy from the hot waste gases. This is valid for the EAF mini mills as well as for the integrated route. Various examples for waste heat recovery systems including resulting benefits are discussed for the EAF, agglomeration, blast furnace, direct reduction and BOF. New innovative bag-filter systems feature extremely low emission levels at lowest pressure loss and sound emission conditions. Also improved control and automation solutions support the operators to minimize the operation and maintenance costs of their off-gas system. Steelmaking by-products shall not be considered as residues, but as a valuable and cheap raw material source. The paper presents some show cases how to valorize slags as well as utilizing coke and iron oxide fines to increase productivity and minimize raw material cost. A new process for highly flexible converter steelmaking allowing for extraordinary high HBI and scrap rates above 50% and improved yield is discussed and evaluated

Oct 30, 2017

By Claudio Pereira Diogo

A lot of galvalume/aluzinc steel sheet was furnished to a metallic roof manufacturer intended for tile fabrication. But, according with the roof manufacturer, that coils develops a different superficial aspect during processing. The purpose of this work was to provide an explanation for the appearance of the observed surface on one side of the coils. In order to find out the origin of the problem, mechanical and microstructural characterization tests were done at INSPEBRAS with the support of a partner laboratory. The results are described in this paper with their analysis and conclusions.

Aug 16, 2017

By Lucas Breder Teixeira

O uso de ferramentas de simulação numérica para análise estrutural vem se expandindo nos últimos anos, sobretudo utilizando o método dos elementos finitos. Nesse trabalho são apresentados dois exemplos de otimização de projetos envolvendo componentes de mecanismos de válvula gaveta, realizados pela Magnesita Refratários S.A. Partindo da geometria inicial até o produto final, é analisado como o campo de tensões é adequado a valores admissíveis, conforme modificações de projeto são realizadas. Por fim, é demonstrada a importância desse tipo de estudo para alcançar maior confiabilidade e segurança em projetos mecânicos.

Aug 16, 2017

By Jean-Paul Simoes

The development of the blast furnace over the last years lead to a substantial increase in production capacity and productivity. This development triggered an evolution of the cooling systems in order to cope with the raising heat loads. The excellent protection of the shell by copper staves allowed blast furnace operators to achieve campaign lifetimes of more than 20 years. However in recent years some blast furnaces have experienced severe wear of the copper staves due to abrasion. The influences of the blast furnace design as well as of the operation conditions on this premature wear have been analysed and the mechanisms leading to the wear will be explained. New developments in the copper stave technology are part of the solution for avoiding premature wear during periods with less favourable conditions. The protection mechanisms made available by the new design extend the inherent protection mechanisms of copper staves to these periods. BFXpert® system is the ideal tool for the monitoring of the process data, the process models and the recommendations given by Sachem® support the operator in choosing efficient operation points. The charging with a Bell Less Top® (BLT) allows an accurate controlling of the blast furnace with regard to the optimization of the gas distribution. High performance operation together with long campaign lifetimes are thus made possible.

Aug 1, 2018

By Francisco de Paula Pinheiro

Estudo das fontes de variação do processo de vazamento contínuo de chapas de alumínio, através da aplicação de uma metodologia prática e rápida para solução de problema. Após identificação das variáveis críticas à qualidade, ações foram tomadas de modo a minimizar as perdas do processo, o que contribuiu para a redução nos custos de produção das chapas.

Aug 16, 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 Adriana Amaro Diacenco

This work presents the finite element modeling of Euler-Bernoulli beams constituted of a metallic material, discussing theoretical and numerical aspects. The numerical analysis uses Hermitian interpolation functions and finite elements with two degrees of freedom per node. A numerical simulation will be done for uniform loading considering two kinds beams (steel and aluminum). The paper is organized as follows: introductory comments and numerical simulations to evaluate the static and dynamical behavior of the metallic beams.

Aug 7, 2018

By Yuechang Wang

A new method of manufacturing the wavy-tilt-dam(WTD) mechanical seal has been mentioned. In this method, the special equipment is designed to provide a predetermined force to external and inner circular surface of the ring. After milling the end face of the seal by grinding miller and releasing the preload, the wavy-tilt-dam can be done on the seal surface. In this paper, a prediction model is built up to investigate the relationship between the predetermined force and the deformation on the surface of the ring by using ANSYS software. A WTD ring is manufactured by this method which approves that the prediction model is in accord with the real process and this manufacturing method of the WTD mechanical seal is a proper choice.

Jul 31, 2018

By Jean François Stumper

This paper presents the TMT “3D TopScan” profilemeter, which is a Radar-based profilemeter that measures the total burden surface within a few seconds and on a continuous basis. This equipment is based on an electronically steered solid-state radar scanner, such that a very large amount of surface data is collected within short time intervals. These new electronically steered antenna systems are the key to meet the demands for both accuracy and speed. The TMT probe is installed at a fixed location at the top cone, such that it does not interfere with the charging, enabling a continuous measurement and a compact design.Blast furnace charging optimization can be achieved based on its measurement data. The burden surface is continuously measured every few seconds, enabling the blast furnace operator to detect any details including asymmetries or irregularities in the surface pattern. A variety of process analysis tools are available. Due to the continuous and fast measurement, the burden descent speed can be supervised without process interruption on an ongoing basis. More accurate process models (layer models) than ever are obtained which fully consider the unsymmetries.This technology, developed by TMT Tapping Measuring Technology, is successfully in operation at Salzgitter Flachstahl GmbH at their blast furnace B. The probe and the data evaluation tools combine today’s technological capabilities in measurement technology with the practical requirements of blast furnace operation.

Aug 16, 2017

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