Abstracts - Billet Process Track
Click on the abstract title to see the author name(s) and description.
| BP033 Identification of the Most Influencing Parameter for Perfect Extrudability of High Strength 6082 |
BP098 Game Changer for Extrusion Billet Surface Quality |
|
| BP054 Continuous Homogenizing Furnace Utilizing Vertical Airflow to Improve Temperature Uniformity and Increase Processing Flexibility |
BP120 A Method for Analysis of the Metallic Particles Found within Extruded Profiles |
|
| BP070 Industrial Test of Ti-C-Al Grain Refiner |
BP121 Common Billet Defects and Their Causes |
|
| BP077 Influence of Billet Processing on Extruded Section Properties |
BP164 The Challenging Evolution of High Quality Gloss Alloy—Type Extrusion Billets |
|
| BP080 Innovations in Billet Casting and Homogenization |
BP175 Optimizing Combustion Systems for Aluminum Melting Furnaces |
|
| BP093 History and Future of Aluminum Dross Processing |
BP190 The Effect of Aluminum Molten Metal Cleanliness on the Quality of Aluminum Profiles |
|
| BP094 Evaluation of Efficient Preheating Systems for CFF Boxes and Launders in Aluminum Casthouse |
||
|
Identification of the Most Influencing Parameter for Perfect Extrudability of High Strength 6082 Andreas Schiffl, Hammerer Aluminium Extrusion Industries GmbH, Iris Schiffl, School of Education, University of Salzburg, and Johannes Österreicher, LKR Light Metal Technologies Ranshofen, Austria
The enhanced requirements of the aluminum industry, particularly in the European automotive industry, such as crash performance, short- and long-time stable mechanical properties, corrosion resistance, and recrystallization structure, require modified high-strength 6082 alloys. Increasing amounts of strengthening elements such as magnesium, silicium, chrom, manganese, and copper induce poor extrudability, as well insufficient homogenization. It will be shown the most powerful leverage to raise extrudability to a good level for a given strength, crash performance, stable mechanical properties, and good recrystallization stability. On one hand you can improve the homogenization treatment and on the other hand you can modify the chemical composition to achieve the best extrudability. Developing a good understanding of the influence of different parameters is very important, but the complex coherencies between them are unknown in detail. For identification the most power full leverage, enhanced statistic tools were used to determine the "estimated effect size eta-squared²." The results show the comparability between laboratory-scale (deformation dilatometer specimens), semi-industrial (mini extrusion press) and industrial scale trails and provides insight to understand the importance of these engaged developments. Continuous Homogenizing Furnace Utilizing Vertical Airflow to Improve Temperature Uniformity and Increase Processing Flexibility Keith Boeckenhauer, Seco/Warwick Corporation, USA, and Krzysztof Niemiec, Seco/Warwick Europe, Poland
Plant managers face high quality requirements in the homogenization of extrusion log and billet of 6xxx series aluminum alloys. Two are the most important: - provide uniform structure and sufficient extrudability of the billets within the entire cast, allowing high extrusion speeds and appropriate mechanical properties of extruded profiles, and - obtain good outside surface of the logs without any scratches, damage, oil stains, spots, and other imperfections to maximize metal recovery (yield).
In many cases, casthouse managers are obliged to meet these requirements for a wide variety of log diameters, typically from 6-7" to 14-16". At the same time, they are striving to reduce operating costs, which are mainly related to energy consumption and workforce requirements. SECO/WARWICK, utilizing a vertical air flow continuous homogenizing technology, has developed an original concept for a continuous homogenizing plant. This furnace system provides a more versatile and flexible operation than any other existing solution on the market. The paper presents the concept of this innovative continuous homogenizing furnace system and the benefits it brings to the user in terms of production capabilities, efficiencies, and product quality. Industrial Test of Ti-C-Al Grain Refiner Guilherme Seeber da Rocha, and Douglas Morris Baker, Votorantim Metais – CBA, Brazil
There are several papers showing the potential benefits of Ti-C-Al grain refiner use instead of the classic Ti-B-Al on billets casted for extrusion. Although some producers claim to have benefits on its use, little has been seen that would encourage a major paradigm shift in the industry. In this work, we investigate the effects of Ti-C-Al grain refiner use in normal industrial production flow. We expect to have a decrease in grain refiner consumption due to increased refining capacity of TiC and less wear of extrusion dies associated with better surface finish on extruded profiles due to the lesser formation of agglomerated particles. By these results, we expect to have a more clear evaluation of Ti-C-Al grain refiner gains and a measure of its economic viability. Influence of Billet Processing on Extruded Section Properties Branimir Lela, Igor Duplančić, and Jure Krolo, FESB, University of Split, Croatia
This study deals with the influence of both homogenization time and temperature of AlMgSi1 aluminum billets on maximum extrusion force and surface roughness of extruded sections. Experiments were carried out in accordance with the central composite design of experiments. Experiments for direct hot extrusion were performed on a hydraulic press equipped with a special rig. The time and temperature were varied within interval 30 to 120 minutes and 400 to 530° Celcius, respectively. Final results show that maximal extrusion force increases when both homogenization time and temperature decreases, while maximal surface roughness of the extruded sections was obtained with minimal homogenization temperature and maximal homogenization time. Innovations in Billet Casting and Homogenization Jostein Røyset, Øystein Bauger; Oddvin Reiso, and Ulf Tundal, Hydro Aluminium Research and Technology Development, Norway
A new casting technology that almost eliminates the inverse segregation zone has enabled the development of a homogenization cycle that gives advantages in extrudability and profile surface quality. In homogenization of 6xxx alloys the focus has historically been put on dissolving MgSi, transformation of AlFeSi to AlFeSi, and on spheroidization of AlFeSi particles. An issue that has been largely ignored is the amount of Fe and Mn in solid solution after homogenization. In the present work an overview of several trials is given, in which it is shown that by using homogenization cycles that are designed to minimize the amount of Fe and Mn in solid solution while fulfilling the other criteria expected from proper homogenization, a significant improvement in press performance and profile surface quality can be measured. In order to achieve good transformation degree and spheroidisation, it is necessary to start the homogenization holding segment at a somewhat higher temperature than normal. This requires a billet with very lean inverse segregation zone, in order to avoid melting phenomena at the billet surface. Examples on the impact of the innovations on the surface quality of extruded profile are given. L-Type Immersion Heater Performance Review for Launder Applications William (Guillaume) Levacher, Lethiguel, France; and Bob Eivani, Drache USA Inc., USA
The L-Type, Sialon (Silicon Nitride Sheath) immersion heater is an electrical heater. It could be used in specific applications with dimensional restrictions, especially with shallow molten metal depth like launder applications to maintain or increase the temperature of the molten Aluminum. There are a few advantages in using an immersion heater; it has minimal effects on the metal quality of molten aluminum as sialon is practically non-reactive with aluminum. There is also a built-in thermocouple inside the heater; the heat transfer for immersion heaters uses conduction vs. radiation for other electrical heaters. In addition, sialon has high thermal conductivity, so there would be virtually no overheating of the molten aluminum, which eliminates the formation of oxides and the risk of higher Hydrogen absorption thereby ultimately improving the metal quality. This research the L-type heater has been used inside an aluminum launder and the condition of the molten aluminum with and without the heater has been comparatively investigated for metal cleanliness and hydrogen level using the recent techniques. The reaction level between the sialon sheath and pure aluminum has also been measured in a controlled environment. 6xxx Alloy with High Temperature Stability Jostein Røyset,Aluminum; Oddvin Reiso, Hydro Aluminium Research and Technology Development; Randi Holmestad, NTNU Department of Physics; Calin Daniel Marioara, SINTEF Materials and Chemistry; and Inge-Erland Opheim, Steertec Raufoss AS, Norway
The present work gives an overview of the development and properties of a new 6xxx extrusion alloy with high temperature stability. Such alloys are particularly useful for automotive applications, as better high temperature properties facilitate the replacement of heavier materials with aluminum. The 6xxx alloys get the majority of their strength from precipitation hardening. A detailed investigation by transmission electron microscopy reveals that the high temperature stability of the properties is intimately linked to which type of precipitate that is formed prior to or during the high temperature exposure. By optimizing the alloy for formation of a particular precipitate type, the deterioration of properties after long-time exposure at high temperature is minimized. An application where the alloy is particularly useful is for automotive intermediate steering shafts. The main components in these assemblies may be forged from extruded round-bar. Examples of product testing are given, showing that the strength and fatigue properties are on level with the 6xxx alloys in the new condition, and that the components fulfill the manufacturers’ long-term temperature stability requirements. An aluminum design based on the new alloy holds the potential for replacing steel, which usually would have been chosen. History and Future of Aluminum Dross Processing David J Roth, GPS Global Solutions, USA
This paper reviews the history of the generation and handling of aluminum dross from the 1960s to present day technologies, documenting nearly 60 years of progress in the management of this valuable component of aluminum production. Covered will be all the past methods for recovery of the aluminum from this material and the movement to greater metal preservation and alternative uses and processes for recovery of the aluminum oxide fractions of the dross. An up-to-date review of all current technologies will be detailed as the industry moves towards not only minimization of dross generation but also 100% recovery of all the materials that make up dross. In addition, future technologies on the horizon will be discussed to stimulate thought on how aluminum dross volumes will diminish with new technologies and change from being a waste to a resource for aluminum scrap smelters and primary aluminum smelters. Evaluation of Efficient Preheating Systems for CFF Boxes and Launders in Aluminum Casthouse Jochen Schnelle and Frank Reusch, Drache Umwelttechnik GmbH, Germany, and Bob Eivani, Canomac Inc., Canada
Efficient preheating of CFF boxes, launders downstream of the casting furnace as well as casting table refractory have received a stronger focus over the recent years. Fast, reliable and energy-efficient heating systems can prevent numerous problems during the casting process, reduce cost and save time and energy, for example, an inefficient preheating system could cause: excessive amount of heat loss at the start of the cast, metal freezing inside the ceramic foam filter during the filter priming process and non-uniform temperature distribution on the casting table. A number of technologies and solutions for launder and filter box preheating are presented and discussed in this research, and their cons and pros have been evaluated. Game Changer for Extrusion Billet Surface Quality Arild Håkonsen and Rune Ledal, Hycast AS; John Erik Hafsås and Jostein Røyset, Research & Technology Development, Hydro Aluminium, Norway
A new casting technology, Low Pressure Casting (LPC), for aluminum extrusion billet casting has been developed by Hydro Aluminum and Hycast. The new technology produce billets with dramatically improved surface quality. The technology is validated through production in three casthouses in regular production. The technology is verified for soft and hard alloys in the dimension range Ø127-520mm (5-20.5?). The new technology uses siphon feeding of liquid metal to the casting moulds, and has thus eliminated the metallostatic pressure in the liquid metal inside the molds. The surface quality is significantly increased compared to billets cast with conventional technologies since exudation of enriched residual melt on the billet surface is eliminated. The surface segregation is significantly lower in depth and in alloying element enrichment compared to billets produced with conventional gas-assisted graphite wall molds. For hard alloys, normally produced with conventional molds with no gas, the quality difference is even bigger and turning/peeling off surface material of billet might be eliminated for direct extrusion applications. The improved surface quality has the potential of giving increased yield and productivity in the extrusion process. Extrusion trials have revealed less tendencies of inflow for all alloy groups, and thus the need for shorter butt-end cutoffs. A Method for Analysis of the Metallic Particles Found within Extruded Profiles Pawel Kazanowski, SAPA Precision Tubing Technology Center; Eskild Hoff, Hydro Technology Center, and Richard Dickson, Hydro Aluminum Metals USA, USA
Various inclusions are sometimes found within extruded profiles. The origin of these objects is often difficult to identify and profiles with embedded particles are shipped without detection. In many cases, the profiles fail to perform and only during a detailed failure analysis are these particles found. It results in considerable economic and production losses in the aluminum extrusion industry, and is a major quality detractor. Sometimes the inclusions found are metallic particles that are used to handle the molten aluminum metal and are also used for aluminum extrusion tooling. The research focused on finding a method to distinguish the metallic particles originating from the casting process and hot aluminum extrusion process. Extensive metallographic analysis of the interfaces between aluminum and the objects was performed. These examinations provided enough information to establish and verify the equation for the intermetallic layer thickness growth using the parabolic low. A very good agreement was established between the intermetallic layer thickness and the time to create it. The proposed method is very easy to use and provides enough information to support the root cause analysis for the extruded profiles with embedded particles found after production. Common Billet Defects and Their Causes John D Schloz, Viking Metallurgical LLC, USA
Modern aluminum producers in all areas require metal of the highest quality with regard to cast billet defects. Substandard metal quality can cause or contribute to billet cracking, surface defects, sub-surface defects, or poor grain or intermetallic phase formation. These in turn cause a host of negative issues in downstream processes such as homogenization, extrusion, finishing, or heat treating. The presence of defects in the billet casting process represents one of the greatest sources of frustration to operators, process engineers, and management alike. Much effort has gone into understanding and correcting these defects, yet they continually crop up in all but the most tightly controlled environments. All defects have the potential to disrupt operations and cause significant loss of time and money while presenting a risk to customer satisfaction and trust. In order to both solve and prevent these problems, it is necessary to understand the mechanism for defect formation, as well as the root causes that influence the defect formation process. Additionally, casthouse technical management should understand the impact of the different classes of casting defects on the various downstream processes, and be able to articulate them to higher levels of management. Preventing Molten Metal Explosions in the Extrusion Industry Alex Lowery, Wise Chem LLC, USA
Molten metal explosion hazards have been underestimated in the aluminum extrusion industry for far too long. P.D. Hess and K.J. Brondyke, “Causes of Molten Aluminum Water Explosions and Their Prevention” research findings have long been forgotten. This paper addresses the issue of molten metal explosions originating on concrete, steel and stainless steel substrates with special attention on industry best safety practices of mitigating this hazard. Specifically, in this paper I will be looking at the history of molten metal explosions, research studies, and the use of a specific organic coating, which can prevent molten metal explosions from occurring. I argue that numerous incidents in our industry where molten metal explosions have occurred could have been prevented. The Challenging Evolution of High Quality Gloss Alloy-Type Extrusion Billets Marcel Rosefort, Thien Dang, and Hubert Koch, TRIMET Aluminium SE, Germany
One major business of the German aluminum industry is to provide the aluminum processing industry with rolling slabs, extrusion and forging billets. Due to the demand for high quality regarding these products in particular of the automotive industry it is essential to enforce and secure the quality control. The gloss alloys are especially characterized by an extremely homogenous microstructure without internal defects or inclusions. Gloss alloys are high purity aluminum extrusion alloys. This material composition and the special processing know-how allow a considerably higher productivity. Due to optimal polishing and brightness properties as well as an excellent bending quality the gloss alloys are especially appropriate for the production of surface sensitive components like trim parts, roof racks, decorative fittings, door handles, cover plates. These gloss alloys allow any surface treatment from anodizing to coating. The production of such alloys requires highest quality standards, the best raw materials and continuous improvement concerning process and material.
The paper covers the production of these special extrusion alloys including quality requirements, qualifying of the alloying material, and process parameters. Second focus is the research and development activities concerning laboratory examinations, inclusion identification and casting technology for optimizing the gloss alloy quality. Optimizing Combustion Systems for Aluminum Melting Furnaces Jim Checkeye and Matt Valancius, Bloom Engineering Company, Inc., USA
Aluminum companies are continually discovering and implementing innovative ways to minimize operating costs and increase production. In order to achieve these goals, the entire process must be analyzed. This paper will specifically evaluate processes related to the aluminum melting furnace. What combustion technologies should the company consider (cold air, recuperative, regenerative, oxygen-fired, oxygen-enriched?) What are some cost effective ways to melt aluminum? What are optimal burner and furnace configurations? The paper will analyze several new technologies and melting techniques, including:
The Effect of Aluminum Molten Metal Cleanliness on the Quality of Aluminum Profiles Cenk Sönmez and Emrah Fahri Özdoğru, BCM Makina & Kimya, Turkey
Process parameters should be systematically controlled and optimized in the aluminum extrusion process in order to get a high quality product; however, there could be some cases in which that is not enough to take control of the extrusion process. The quality of the billet, which is the raw material for producing the profile, is one of the most important issues. Although the metallurgical structure of the billet has been given necessary importance in aluminum casting over the last few years, there has not been new research on molten metal cleaning and the effect of cleaning on the quality of the profile. Today, the production techniques are well defined and clear, and the process method of the billet producers directly affects the quality of the molten metal and, therefore, the quality of the billets. In this study, the effect of the impurities coming from fluxes, grain refiner and ceramic foam filter has been analyzed and shown in real industrial profile samples.
|
||
