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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 Maurilio Pereira Gomes

The aim of this work was to heat treat and characterize sintered valve seat inserts (VSI). The powder metallurgy route was the only way found to substitute cobalt and lead, used in the VSI original alloy, due to their high cost and toxicological effect, respectively. The studied VSI was obtained with AISI M2 high-speed steel powder mixed with iron powder and other additives such as manganese sulphide, graphite, zinc stearate, carbides and copper, which was added by metallic infiltration. All the VSI were air quenched and double tempered, for one hour each, at seven different equidistantly temperatures, ranging from 100 °C up to 700 °C. The physical and mechanical properties were evaluated by means of the VSI apparent density, apparent hardness and crush radial strength. The chemical composition was determined through gas analysis, for the light elements such as carbon and sulfur, and energy dispersive X-ray fluorescence spectrometry for other elements. Microstructural characterization was performed with the support of scanning electron microscopy and energy dispersive spectroscopy. Regarding the VSI final application, the best results were achieved with the inserts air quenched and double tempered at 600 °C.

Oct 30, 2017

By Daniel Carvalho, Marcos Viana, Leonardo Demuner, Herbert Castro

Intensive process and technology improvements related to the BOF converter — the key process to increase steel plant productivity and stability — have been performed at Ternium Brazil. This paper details the road map for process developments and investments in equipment technology, as well as the results achieved. The main topics of this development are the process control and optimization systems, slag forming model, oxygen blowing pattern, end-of-blow point control and slag carryover control. The outcomes of this development are improvements in the reblow rate, end-of-blow oxidation, direct tapping, slag carryover, slopping ratio, metallic yield and lining life.

Oct 1, 2019

By Álvaro Lúcio

This paper outlines the DPC process as na economic and environment friendly option for the use of cultivated forest as a source of raw material for metallurgical charcoal.The DPC process was specially developed to bring logistic, environmental, technical, economic and global energy efficiency when compared to termal1 the existing biomass carbonization process. The DPC process utilizes the volatile materials (condensable and non condensable) as a source of the energy required by the carbonization process guarantying its complete combustion. As result the DPC process avoids the burning of termal1 the loaded wood, obtaining a higher charcoal to biomass yield, and avoids the emission to the atmosphere of polluting gases. Gases emitted by the carbonizing wood have na energy termal1e enough to dry the wood soon after its harvesting. By avoiding the storage in the field during na average of 150 days, the resulting economy is quite significant. As a termal1e1 the higher charcoal to biomass yield na termal1e1e economy is obtained through the reduction of the cultivated forest term. This paper emphasizes the economic advantages of the DPC process.

Aug 16, 2017

By Frenk van den Berg

In the manufacturing of steel strip for the automotive sector, the mechanical properties are largely defined by the process conditions in the hot strip mill. In particular the phase transformation, from austenite to ferrite, which takes place during the forced cooling stages on the run out table (ROT) after the finishing mill, governs the microstructure and hence the mechanical properties.In current practice, metallurgical models are used to predict the phase state at each position in the strip. These model predictions are supported by pyrometer measurements along the ROT. Although reliable in the majority of the situations, both measurements and models sometimes have difficulties in providing robust output. In this paper, we present a new type of inline measurement, which directly measures the amount of phase transformed. The instrument is based on a technique known as impedance spectroscopy. As result of a collaboration of different institutes and companies, the equipment is robustly running during several years exclusively in the Hot Strip Mill of Tata Steel in IJmuiden.

Aug 16, 2017

By Kurt Herzog

State-of-the-art automation information technology and connectivity enables the digitalization of steel production that goes far beyond conventional automation of industrial production. Initiatives have been started around the globe to foster digitalization like IIoT (Industrial Internet of Things) in the US, Industrie 4.0 in Germany or China 2025. Primetals Technologies is actively driving the digitalization shaping the future of steel production. Intelligent combination of sensor technology combined with digital models as well as quality and production planning and control systems leads to new dimensions in product quality and production cost reduction. New diagnostic ways allow intuitive fault tracing or processing to support faster maintenance. Digital assistants support both operation and maintenance using context-oriented or self-learned information.

Oct 30, 2017

By Andrelio Marcos Ribeiro, Lucio Ribeiro Camisao, Antonio Carlos Ataíde, Alan de Sousa Pereira, Renato Siqueira Campos

The annealing and pickling line n. 1, responsible for the production of stainless steel 3xx, 4xx and 430a in thicknesses from 4 to 0.4 mm, has two vertical strip accumulators. These are intended not to let the material exceed the determined time in the furnace and in the pickling, and consequently do not cause defects like burning and excessive pickling. Strip accumulator n. 1 avoids the line from stopping during welding execution of the coils in the welding machine. In sequence, the strip accumulator n. 2 avoids the line from stopping at the end cutting of the tips, and in the coils removal from the pickling. The strip accumulators have a roller table that during the strip accumulation moves vertically downwards while its counterweight moves vertically upwards, and do the inverse movement when the material is released. On December 12th 2018, the failure occurred in the strip accumulator n. 1, where it was verified that the shaft of one of the pulleys had been fractured by high-cycle mechanical fatigue, which was characterized by alternating bending. With the fracture of the shaft, occurred the unevenness of the counterweight that damaged the guides. Failure analysis of this occurrence was based on the PDCA methodology, when was verified a weld between the shaft and the pulley. The analysis of the microstructure transformation in the molten zone, in the heat affected zone and in the base metal was carried out in an optical microscope, and no abnormality was observed. It was also carried out the end test by penetrating liquid, finding an inadequate weld in its geometry, as well as longitudinal trunks along the center of the weld bead. However, after a huge investigation of the causes, it was found that the failure was triggered by an inadequate design of the pulley shaft. It was also verified that the shaft had an open measure, inadequate for the operational context. After the analysis, action plans were drawn up based on the FMEA methodology to inhibit the failure recurrence.

Oct 7, 2019

By Jesús A. Carlos Cornelio

Since their discovery in 1991 Carbon nanotubes (CNTs) have attracted much interest due to their remarkable mechanical, thermal, electrical, chemical and optical properties. In connection with their mechanical properties, CNTs have been studied in various forms for tribological applications including their use as lubricant additives for oil and water. In this paper the tribological properties of CNTs (SWCNTs and MWCNTs) when used as lubricant additives are studied under rolling-sliding conditions in a twin-disc testing machine. The tests were performed using 5% of creepage and pressures of 0.8 GPa and 1.1 GPa. Used functionalized nanotubes were modified with carboxylic acid ultrasonically dispersed at different concentrations (0.01, 0.05%). The results indicated that the presence of carbon nanotubes leads to a decrease in both friction coefficient and wear rate for both systems studied (oil and water).

Jul 31, 2018

By Thomas Germershausen

Worldwide BOF-based steel plants are faced with demanding environmental requests and rising energy costs. For cleaning of primary gases from the BOF the scrubbing technology is worldwide adapted. For wet-scrubbers there is a direct relation between pressure loss and achievable clean gas dust content. Subsequently main energy consumers within Gas Cleaning Plants are the driving fans. To evaluate actual performance and to identify optimization measures extensive field measurements at existing Gas Cleaning Plants were performed. The operational results from various BOF plants worldwide will be presented and benchmarked. As a conclusion, advanced control strategies for reduced energy consumption and lower environmental impact were developed and implemented.

Jul 30, 2018

By Emanuelle Garcia Reis, Gustavo de Sousa, Rodney Pardo Alves

Gerdau Ouro Branco´s plate mill started the operation in 2016 with high level technology. In general, national and international plate markets are every day more rigorous about final product quality. Suppliers must be aware about dimensional accuracy, surface quality and flatness of the plates, independent of the quality standards. To guarantee the best service to this increasingly demanding and competitive market, it is extremely important to guarantee the original project conditions executing the right maintenance of the rolling mill main components. In order to maintain the product quality and avoid the production and maintenance cost increase, it is important to find ways to control the mill and the main process variables, through daily measurements of the equipment performance. This paper aims to present the influence of the main equipment variables that affect the mill operational stability and how to control and evaluate the mill performance.

Oct 1, 2019

By Felipe Beluche Lima, Caio Augusto Silva Santos

Brazil is the largest producer of crude steel in the Americas by BOF process and many challenges come along with the increasing market demand. In the BOF, a tubular wall hood structure has been showing premature failures related to the overlay welded tube technology placed in the hood wall. The main root causes were: thermal fatigue at 1800°C, hot spot formation, high heat-affected zone (HAZ) leading to susceptibility of stress cracking, carburizing corrosion and superficial wearing. Based on that, co-extruded tube technology (named composite tube by Sandvik) was the alternative chosen to enhance hood performance without compromising BOF process. In order to rises safety and productivity, composite tube has 100% metallurgical bond assuring stable expansion, high heat exchange efficiency, better corrosion resistance and less rough surface finishing. It was highly suggested to many others mills due to similar and already existing reported cases.

Oct 1, 2019

By Santiago Faucher

Molten slag from pyrometallurgical furnaces is tapped at high temperature, carrying a large amount of thermal energy. But the common slag dumping and water granulation methods used for slag treatment do not permit energy recovery. Furthermore, water is present in these processes and while operations are designed to minimize risks of steam explosions, from the contact of slag with water, these common slag handling practices have never been inherently safe. Common handling practices do permit some slags to be sold, but often in low volumes at low prices. Dry granulation offers advantages over these common slag handling practices, including the production of by-products, the recovery of thermal energy, and the eliminated consumption and safety hazards of water. For these reasons, there have been various studies in dry granulation and heat recovery, but most have never been brought to commercial scale due to scalability and cost challenges. Ecomaister- Hatch has developed and brought to commercial scale a reliable and simple dry granulation and heat recovery technology. Here we review common slag handling practices, the developments in dry slag granulation over the last three decades, introduce the Ecomaister-Hatch dry slag granulation process, and elaborate on future applications of the technology in the processing of argon oxygen decarburization and blast furnace slags.

Aug 17, 2017

By Thomas Schanz

Current steel market conditions require small investments only to lower operational cost. SMS Concast has developed new products which optimize continuous casting process cost for long product steel production. This paper describes a selection of three products. All three systems are patented (patent pending for CONDRIVE). CONSAFE, a non-radioactive mould level measurement system for reliable mould level measuring on open stream casting CCM’s; CONSTIR-MWS, an improved control software for electromagnetic stirrers which lowers energy cost by 35%; CONDRIVE, a brand new oscillation drive system which provides the features of a hydraulic oscillator, however with a cost efficient electric drive.

Aug 17, 2017

By Joachiim Lehner

The application of post-combustion (secondary oxygen) to avoid skull formation on BOF lances was tested in industrial trials. The main findings are that no negative impact on the metallurgical targets (i.e. carbon, temperature and phosphorus at end of blow as well as iron–oxide in the slag) could be observed. The technology is capable of avoiding the buildup of lance skull and consequently increasing the average life of lance tips. The application of post-combustion not only affects the skull formation, there are also interactions with the refractory lining, especially thermal wear, and the utilization of the process gases (CO Recovery) that have to be considered. Special attention has to be paid to the parameters determining the use of secondary oxygen because rather small changes can strongly affect the points mentioned above. Since August 2016, the PCD (Post-CombustionDistributor) lances are used on a daily basis in the steelplant LD3 in Linz.

Oct 30, 2017

By Alessandro Pigani

Over the last 25 years the thin slab casting and rolling process has been gaining a major market share in the production of hot rolled strip, progressively eroding the areas previously of exclusive domain of conventional mills. This is mainly thanks to the competitiveness of the process over conventional ones, and to the growing ability of this technology to cover the majority of market niches, well beyond the boundaries of the commodity market. After having significantly contributed to the continuous expansion of this production mode and after an extensive campaign of theoretical research and physical testing in reference plants, Danieli has progressively developed over the years a new generation of thin slab casting and rolling layout, marking a new phase in the evolution of this process. The new step-ahead is epitomized by the name QSP-DUE. This configuration belongs to the Quality Strip Production (QSP) family, which is Danieli’s strip-quality-oriented thin slab based plants. The innovative features of the process are embodied in the acronym DUE, which stands for Danieli Universal Endless (Danieli patented technology – US patent n. 8087449, January 3rd, 2012). What makes this new concept different is the ability of “universal” rolling modes thanks to the fact that, now, within one single plant it is possible to perform coil-to-coil, semi-endless and endless rolling modes, making this plant a major technology innovation compared to the previous generation.

Aug 16, 2017

By Theodore James Kurela

Analysis of adverse technical issues has traditionally relied on a snapshot of the state of the operation complemented with both the melt shop’s archived data and eyewitness accounts of adverse events. The GrafTech ArchiTech System is helping EAF shops solve problems faster by combining continuous analysis of information with statistically based alerts of process deviations. After one year of system implementation, a number of cases have been detected and communicated to melt shops worldwide. The objective of this paper is to examine a few of these cases; the early detection, statistical analysis, deviation reporting and the resulting countermeasures implemented.

Aug 17, 2017

By Simon Chiartano

A global reflection on the design of blast furnace main runner was investigated in this paper. TRB Company used its skills and expertise to understand what the best option for this sensitive component is, including some innovative tools: intelligent block design for safety lining, thermal & thermomechanical numerical simulation, immersive measurement by thermocouples, IR thermal camera, 3D laser scanner.

Oct 1, 2019

By Henrique Silva Furtado

Light meter is an ArcelorMittal innovation that uses off-gas light intensity to predict bath carbon, which is akin to the visual cues that the operators employ to finish a blow. Light meter enables the prediction of end point that is independent of any operator’s judgment. The results have been in general consistent with the actual carbon content at BOF end point at Tubarão. Besides some outliers that occurred due to strange intensity curves, the system implemented in Tubarão BOF 3 reported a carbon prediction error statistic that is very similar to dissolved oxygen–carbon end point statistics. Preliminary trials using light meter without any filter improved carbon hit ratio significantly.

Jul 30, 2018

By Andreas Volkert

Energy efficiency, equipment reliability and cost reduction are of the key factors in any efficient plant. Badische Stahlwerke (BSW) started using its own burner technology in 2001, this was developed by Badische Stahl-Engineering (BSE). Over the past 15 years, Badische improved all aspects of its Virtual Lance Burner (VLB), to perfectly fit all steelmaking requirements. This tiltable VLB was first tested at BSW’s electric arc furnace no. 2 in 2012. Promising results like reduction of refractory wear, energy efficiency, reliability, etc., were obtained. At the same time the existing VLB system was further improved with regards to the design of the water-cooled copper box. Today in 2016 both EAFs at BSW are equipped with the new patented tiltable system and the new copper box design. The paper will describe the results of the past years at Badische, but will also show the performance at other installations.

Aug 17, 2017

By Jorge Madias

Neste trabalho se leva a cabo uma revisão da literatura sobre defeitos em beam blanks. O foco é no mecanismo de formação e as soluções propostas para diminuir sua ocorrência. Os defeitos superficiais incluidos são as trincas longitudinais e transversais, bleeding, pinholes e escória. Os defeitos internos levados em conta são os blowholes, as trincas centrais e as trincas nas pontas das abas. A revisão incluie as técnicas utilizadas para pesquisar os defeitos: caracterização metalográfica, CFD, modelagem termodinâmica e termomecânica, etc. As medidas adotadas estãorelacionadas a mudanças no sistema de lingotamento (por exemplo o design da vâlvula submersa), design do molde, mudanças e regulação do resfriamento secundário, suporte dos veios.

Oct 30, 2017