DOCSLIB.ORG

Premium Rolling Slabs for Premium Rolled Products

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Premium Rolling Slabs for Premium Rolled Products 08 Technology Electro Magnetic Casting-Pit (EMC) at AMAG Premium rolling slabs for premium rolled products AMAG rolling slabs achieve the highest quality standards. This article gives a Possible types of inclusions review about essential and quality-decreasing inclusions appearing during pro- for EN AW-7075 duction of rolling slabs of the alloy EN AW-7075 and how to avoid them [1,2]. AMAG understand itself as an expert in minium alloys. For this purpose, com- Non-metallic inclusions the field of hardening aluminium alloys. prehensive knowledge of the formation • Al 2O3, MgO, Al 2MgO 4 As a premium supplier, AMAG produces mechanisms for each type of inclusion is • Carbides high-strength sheets and plates for aer- required in order to avoid inclusion gen- • Silicates ospace and sportive applications. Fur- eration as well as for efficient melt treat- • Reacted and non-reacted thermore, 7xxx series alloys (e.g. AMAG ment actions. Exemplary, the formation refractory material ® TopForm UHS) can be used in ambitious mechanisms of non-metallic inclusions • Salts (NaCl, KCl, MgCl 2) and light weight structure elements after half are mostly process step independent, e. chlorinated oxides warm forming. For a first class rolling g. oxide generation depends only on the • Graphite product, a first class casting microstruc- presence of oxygen or an oxygen carrier • Aluminium nitride ture is a precondition, which is not only in- (ambient moisture). In contrast to this, • Bone ash fluenced by the chemical composition and the formation of inter-metallic inclusions solidification conditions, but also by avoid- is strongly depending on melt composi- Oxide films ing unwanted influences like inclusion tion and temperature. • Al 2O3 – aluminium oxide content etc. The following article gives a • MgO – magnesium oxide short introduction in the complex topic of After successful inclusion removal actions, • Mixed oxides (Spinel) inclusion formation mechanisms and the the avoidance of inclusion re-entry has to responsible influences. be ensured by an optimized design of the Intermetallic inclusions process chain in order to guarantee the • TiB 2- Agglomerates Inclusions are representing separated customer oriented product quality. The box • Cr-Aluminides phases of particles or clusters in the below gives an overview about possible • Non dissolved alloying elements microstructure of aluminium and alu- types of inclusions. e. g. Cr- u. Ti-pre-alloys Technology 09 Non-metallic Inclusions and Oxide Films Nonmetallic inclusions and oxide films, • Magnesium Oxide – MgO generation are organic substances and which have to be considered in a separate Due to the related character of aluminium carbon in contact with liquid metal. The fol- way, are representing the main group of and magnesium the formation of mag- lowing important sources for carbide gen- inclusions. They usually cover 90 to 95 % nesium oxide happens also by the three eration are known: reaction of oil or other of a typical inclusion spectrum. mechanisms discussed above. Compar- organic substances which are covering ing the formation tendency of Al 2O3, MgO scrap, reaction of melt with silicon carbide • Aluminium Oxide – Al O 2 3 and Al 2MgO 4, magnesium offers a higher (heating elements or refractory material), Aluminium tends to oxidise in the presence driving force for oxidation. In combination reaction with graphite components (impel- of pure or bounded oxygen (e. g. water va- with the subsequent reaction to spinel, lers for gas purging treatments) and reac- pour, metal oxides) to aluminium oxide. In both types of magnesium oxides are most tion with carbon which comes along with common casthouse practice three main responsible for the input of non-metallic alloying elements (e. g. silicon). mechanisms for the formation of alumin- inclusions to the melt. The generation of ium oxide are known: MgO can also be caused by the vaporiza- • Silicates – SiO 2 tion of magnesium combined with a follow- The presence of little silicon dioxide par- Reaction with Atmospheric Oxygen ing oxidation [8]. ticles (< 5 µm) can be related to the Due to the fact that the contact between charged material and mostly as a product the melt and the surrounding air can hardly • Aluminium – Magnesium of erosion processes on refractory materi- be avoided in normal casthouse practice, mixed oxide (Spinel) – Al 2MgO 4 als. Due to their small sizes, they are not this oxidation mechanism is present per- The formation of Aluminium-Magnesium critical (they do not agglomerate according manently. Furthermore, this chemical re- mixed oxide spinel can happen according to their spherical shape). action is not only restricted to aluminium: to four different mechanisms [1,2]: Melt all oxygen-affine elements, like magne- Oxidation, Reaction of MgO with Al 2O3, sium, are reacting to their oxides: Reaction of Melt with Refractory Material and Reaction of Melt with Al 2O3. The first 2 Al (l) + 1½ O 2 (g) g-Al 2O3 (s) mechanism represents the main formation mechanism. During oxide formation within the melt/ air-layer on the bath surface, amorphous Spinel-formation can occur after the rip- oxide films are generated [3]. This modi- ping of the protective oxide layer on the fication is absolutely stable on dry air [4], bath surface, which leads to a direct con- however, on humid air the crystalline al- tact of aluminium and magnesium with lotrope g-Al 2O3 is formed after a certain oxygen from ambient air. The reaction can incubation time (5 to 10 min at 750 °C happen directly by oxidising the elements [5,6]). The incubation time is going to be reduced by increasing temperature, Mag- 2 Al (l) + Mg [Al] + 2 O 2 (g) Al 2MgO 4 (s) nesium content and humidity. or stepwise Reaction with Air Moisture This oxide formation mechanism is strong- Mg [Al] + ½ O 2 (g) MgO (s) ly dependent on ambient conditions and additionally causes a disposal of hydrogen. 2 Al (l) + MgO (s) + 3/2 O 2 (g) Al 2MgO 4 (s) 2 Al (l) + 3 H 2O (g) Al 2O3 (s) + 6 H (g) 2 Al (l) + 4 MgO (s) Al 2MgO 4 (s) + 3 Mg [Al] Reaction with Metal Oxides with or without a pure oxygen source. The reaction of aluminium with oxides is strongly driven by the oxygen affinity of • Aluminium Carbide – Al 4C3 the containing metal ion. If the affinity is Aluminium Carbides Al 4C3 usually come less than the one for aluminium (at 700 °C: along with primary aluminium. They are CaO > MgO > Al 2O3 > SiO 2 > all other produced in the Hall-Heroult process oxides [7]), the following reaction occurs: and cannot be fully removed by the metal treatment actions (gas purging treatment 2y/3 Al (l) + M xOy (s) y/3 Al 2O3 (s) + x M (s/l) or filtration). Other sources for carbide AluReport 10 Technology non-reacted refractory material reacted refractory material 100 µm Fig. 1: Refractory particles with reaction zones in a PreFil ® sample • Salts (Chlorides) – chloride. These are almost unstable, which NaCl, KCl, MgCl 2 leads to subsequent reactions [2]. Salt inclusions, especially magnesium chloride, are very critical regarding the fi- Input with Remelted Secondary nal product quality. This is based on the Aluminium fact that some chlorides are liquid at usual Secondary aluminium may contain little melt temperatures and therefore hardly amounts of chlorides due to the melting precipitate in the ceramic filtration unit. process with salt slags. The density of salt inclusions is between 2,0 and 2,16 g/cm 3, whereby they are Salt Treatment floating in the melt. Consequently, this Nowadays, salts with MgCl 2, KCl and NaCl separation mechanism is depending on as main components are used for melt size and therefore time. Therefore, qual- treatment actions instead of chlorine gas. ity problems may occur due to insufficient They are also used before furnace skim- dwell time in the in-line refining steps. The ming to reduce the quantity of metallic alu- formation of chlorides during melt treat- minium in dross. Due to the fact that salts ment generally happens by the reaction are in a liquid state at usual melt tempera- with chlorine. Otherwise, the the addi- tures, skimming actions have to be done tion of salts (additive) or impurities of the very carefully to ensure that no residues charged raw material can be sources for remain on the bath surface. salt inclusions. Slab casting pit Intermetallic Chlorination process During the chlorination process all ele- Inclusions ments with the affinity to chlorine gener- • Reacted and Non Reacted ate chlorides. The formation of aluminium Coarsely dispersed intermetallics are un- Refractory Material chloride is favoured due to the over- wanted inclusions and the formation mech- The applied refractory materials in the supply of chlorine. Since AlCl 3 is thermo- anisms are strongly dependent on the al- aluminium industry can be character- dynamically unstable in the presence of loy composition. Based on the chemical ised as alumina rich with contents of elements with a higher chlorine affinity, composition of alloy EN AW-7075, only 45 to 98 % Al 2O3 in the form of mullite the following subsequent reactions can titanium boride and chromium alumide can (Al 8[(O,OH,F)|(Si,Al)O 4]4) and/or corun- be observed [7]: occur. These inclusions represent hard and dum. The second main component is less ductile particles which above a critical silicon dioxide. As a reason of mechani- 3 Na [Al] + AlCl 3 (g) Al (l) + 3 NaCl (s) size can cause a significant reduction of cal and erosive loading, refractory material product quality. can get into the melt during the produc- 3 Mg [Al] + 2 AlCl 3 (g) 2 Al (l) + 3 MgCl 2 (l) tion process. After that, refractory material • Titanium Boride – TiB 2 reacts to spinel like inclusions with imple- 3 Ca [Al] + 2 AlCl 3 (g) 2 Al (l) + 3 CaCl 2 (s) As an essential component of the grain mented SiO2 phases.
Load more

Recommended publications
  • Transport of Dangerous Goods
    ST/SG/AC.10/1/Rev.16 (Vol.I) Recommendations on the TRANSPORT OF DANGEROUS GOODS Model Regulations Volume I Sixteenth revised edition UNITED NATIONS New York and Geneva, 2009 NOTE The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. ST/SG/AC.10/1/Rev.16 (Vol.I) Copyright © United Nations, 2009 All rights reserved. No part of this publication may, for sales purposes, be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writing from the United Nations. UNITED NATIONS Sales No. E.09.VIII.2 ISBN 978-92-1-139136-7 (complete set of two volumes) ISSN 1014-5753 Volumes I and II not to be sold separately FOREWORD The Recommendations on the Transport of Dangerous Goods are addressed to governments and to the international organizations concerned with safety in the transport of dangerous goods. The first version, prepared by the United Nations Economic and Social Council's Committee of Experts on the Transport of Dangerous Goods, was published in 1956 (ST/ECA/43-E/CN.2/170). In response to developments in technology and the changing needs of users, they have been regularly amended and updated at succeeding sessions of the Committee of Experts pursuant to Resolution 645 G (XXIII) of 26 April 1957 of the Economic and Social Council and subsequent resolutions.
    [Show full text]
  • Determination of Aluminium As Oxide
    DETERMINATION OF ALUMINIUM AS OXIDE By William Blum CONTENTS Page I. Introduction 515 II. General principles 516 III. Historical 516 IV. Precipitation of aluminium hydroxide. 518 1. Hydrogen electrode studies 518 (a) The method 518 (b) Apparatus and solutions employed 518 (c) Results of hydrogen electrode experiments 519 (d) Conclusions from hydrogen electrode experiments 520 2. Selection of an indicator for denning the conditions of precipita- '. tion . 522 3. Factors affecting the form of the precipitate 524 4. Precipitation in the presence of iron 525 V. Washing the precipitate . 525 VI. Separation from other elements 526 VII. Ignition and weighing of the precipitate 528 1. Hygroscopicity of aluminium oxide 529 2. Temperature and time of ignition 529 3. Effect of ammonium chloride upon the ignition 531 VIII. Procedure recommended 532 IX. Confirmatory experiments 532 X. Conclusions '534 I. INTRODUCTION Although a considerable number of precipitants have been pro- posed for the determination of aluminium, direct precipitation of aluminium hydroxide by means of ammonium hydroxide, fol- lowed by ignition to oxide, is most commonly used, especially if no separation from iron is desired, in which latter case special methods must be employed. While the general principles involved in this determination are extremely simple, it has long been recog- nized that certain precautions in the precipitation, washing, and ignition are necessary if accurate results are to be obtained. While, however, most of these details have been studied and dis- cussed by numerous authors, it is noteworthy that few publica- tions or textbooks have taken account of all the factors. In the 515 ; 516 Bulletin of the Bureau of Standards [Voi.i3 present paper it seems desirable, therefore, to assemble the various recommendations and to consider their basis and their accuracy.
    [Show full text]
  • A Comparison of Thixocasting and Rheocasting
    A Comparison of Thixocasting and Rheocasting Stephen P. Midson The Midson Group, Inc. Denver, Colorado USA Andrew Jackson Arthur Jackson & Co., Ltd. Brighouse UK Abstract The first semi-solid casting process to be commercialized was thixocasting, where a pre-cast billet is re-heated to the semi-solid solid casting temperature. Advantages of thixocasting include the production of high quality components, while the main disadvantage is the higher cost associated with the production of the pre-cast billets. Commercial pressures have driven casters to examine a different approach to semi-solid casting, where the semi-solid slurry is generated directly from the liquid adjacent to a die casting machine. These processes are collectively referred to as rheocasting, and there are currently at least 15 rheocasting processes either in commercial production or under development around the world. This paper will describe technical aspects of both thixocasting and rheocasting, comparing the procedures used to generate the globular, semi-solid slurry. Two rheocasting processes will be examined in detail, one involved in the production of high integrity properties, while the other is focusing on reducing the porosity content of conventional die castings. Key Words Semi-solid casting, thixocasting, rheocasting, aluminum alloys 22 / 1 Introduction Semi-solid casting is a modified die casting process that reduces or eliminates the porosity present in most die castings [1] . Rather than using liquid metal as the feed material, semi-solid processing uses a higher viscosity feed material that is partially solid and partially liquid. The high viscosity of the semi-solid metal, along with the use of controlled die filling conditions, ensures that the semi-solid metal fills the die in a non-turbulent manner so that harmful gas porosity can be essentially eliminated.
    [Show full text]
  • Heat Treating of Aluminum Alloys
    ASM Handbook, Volume 4: Heat Treating Copyright © 1991 ASM International® ASM Handbook Committee, p 841-879 All rights reserved. DOI: 10.1361/asmhba0001205 www.asminternational.org Heat Treating of Aluminum Alloys HEAT TREATING in its broadest sense, • Aluminum-copper-magnesium systems The mechanism of strengthening from refers to any of the heating and cooling (magnesium intensifies precipitation) precipitation involves the formation of co- operations that are performed for the pur- • Aluminum-magnesium-silicon systems herent clusters of solute atoms (that is, the pose of changing the mechanical properties, with strengthening from Mg2Si solute atoms have collected into a cluster the metallurgical structure, or the residual • Aluminum-zinc-magnesium systems with but still have the same crystal structure as stress state of a metal product. When the strengthening from MgZn2 the solvent phase). This causes a great deal term is applied to aluminum alloys, howev- • Aluminum-zinc-magnesium-copper sys- of strain because of mismatch in size be- er, its use frequently is restricted to the tems tween the solvent and solute atoms. Conse- specific operations' employed to increase quently, the presence of the precipitate par- strength and hardness of the precipitation- The general requirement for precipitation ticles, and even more importantly the strain hardenable wrought and cast alloys. These strengthening of supersaturated solid solu- fields in the matrix surrounding the coher- usually are referred to as the "heat-treat- tions involves the formation of finely dis- ent particles, provide higher strength by able" alloys to distinguish them from those persed precipitates during aging heat treat- obstructing and retarding the movement of alloys in which no significant strengthening ments (which may include either natural aging dislocations.
    [Show full text]
  • Microalloyed Structural Plate Rolling Heat Treatment and Applications
    MICROALLOYED STRUCTURAL PLATE ROLLING HEAT TREATMENT AND APPLICATIONS A. Streisselberger, V. Schwinn and R. Hubo AG der Dillinger Huettenwerke 66748 Dillingen, Germany Abstract Structural plates with a superior combination of mechanical properties and weldability are the result of a synergistic effect of microalloyed low carbon equivalent composition plus sophisticated thermo-mechanical control process variants or heat treatment during production in the plate mill. The paper considers both the production routes of such plate and the applications based on the beneficial type of microstructure and property profile. Introduction At the beginning of the 21st century sophisticated materials are used in the challenging field of civil engineering, construction and architecture. As an important type of material modern structural heavy plates are considered in this paper in terms of their development, production and use. The understanding of the role of microstructural features in relation to alloying elements, in particular microalloying elements, will be explored. In addition the exploitation of modern facilities in a plate mill, the tayloring of property combinations and the resulting possibilities for the construction industries are explained and illustrated with selected examples. Production of Structural Plates Requirements Made on the Plate Production Process The following requirements are generally made on heavy plate: It must possess: · The specified dimensions within narrow tolerances and with good flatness (thicknesses may range from 5 to 500mm and widths from around 1 to 5m ); · The yield and tensile strength required by the designers (yield strengths from around 235N/mm² to above 1100N/mm² can be specified); · The toughness required by designers which may include low temperature; · Ease the fabrication (e.g.
    [Show full text]
  • A Novel Method for Synthesis of Nano-C-Al2o3: Study of Adsorption Behavior of Chromium, Nickel, Cadmium and Lead Ions
    Int. J. Environ. Sci. Technol. (2015) 12:2003–2014 DOI 10.1007/s13762-014-0740-7 ORIGINAL PAPER A novel method for synthesis of nano-c-Al2O3: study of adsorption behavior of chromium, nickel, cadmium and lead ions A. Shokati Poursani • A. Nilchi • A. H. Hassani • M. Shariat • J. Nouri Received: 30 April 2014 / Revised: 5 November 2014 / Accepted: 22 December 2014 / Published online: 14 January 2015 Ó Islamic Azad University (IAU) 2015 Abstract Nano-c-Al2O3 adsorbent was synthesized by Introduction the novel sol–gel method. The adsorbent was characterized by transmission electron microscope, Fourier transform Heavy metal pollution occurs during different industrial infrared and X-ray powder diffraction. The effects of sev- activities, and rapid industrialization leads to the increase eral variables such as, adsorbent weight, pH and contact of heavy metal concentration in the environment (Rahmani time on adsorption of chromium (Cr6?), nickel (Ni2?), et al. 2010). It can also increase the concentration of heavy cadmium (Cd2?) and lead (Pb2?) ions were studied in metal ions, such as cadmium (Cd), lead (Pb), zinc (Zn), batch experiments. The results showed that the synthesized nickel (Ni), copper (Cu) and chromium (VI) in water nano-c-Al2O3 had a good capacity to adsorb Cr and Pb. resources (Aziz et al. 2008). The toxic nature of heavy The kinetic data were described with pseudo-first- and metals has caused serious health problems for human, and pseudo-second-order models. Three isotherm models, they can accumulate in the environment (Rahmani et al. namely Freundlich, Langmuir and Tempkin, were used for 2010). In addition, recovery and removal of heavy metals analysis of equilibrium data, and results showed that are principal purposes in industry and saving clean water Langmuir and Freundlich models were suitable for resources (Sharma and Tamar 2008; Neghlani et al.
    [Show full text]
  • Rolling Temperatures on Sticking Behavior of Ferritic Stainless Steels
    ISIJ International, Vol. 38 (1998), No. 7, pp. 739-743 Effect of Roll and Rolling Temperatures on Sticking Behavior of Ferritic Stainless Steels WonJIN. Jeom-YongCHOIand Yun-YongLEE Stainless Steel Research Team, Technical Research Laboratories, Pohanglron & Steel Co,, Ltd.. PohangP.O. Box 36, 1, Koedong-dong, Pohang-shi. Kyungbuk, Korea, E-mail: pc543552@smail,posco.kr (Received on December5. 1997.• accepted in final form on February 23. 1998) The sticking behavior of several austenitic and ferritic stainless steels under the hot roiling conditions wasexaminedin detail using a two disk type hot rolling simulator. Thesticking of bare metal to roll surfaces wasstrong!y dependenton the high temperature tensile strength and the oxidation resistance of the stainless steel, Asteel having higher tensile strength and lower oxidation resistance exhibited better resistance against sticking. The sticking occurred in increasing severity in the order of 430J1 L, 436L, 430 and 409L. It was clarified that a high speedsteel (HSS) rol[ wasmorebeneficial to prevent sticking compared to a Hi-Cr roll. KEYWORDS: ferritic stainless steel; sticking behavior; hot rolling; high speedsteel roll; high chromiumroll. l. Introduction 2. Experiments Thesticking phenomenonoccurs frequently during the A sticking simulator wasused to investigate the effect hot rolling of ferritic stainless steels, causing surface of hot rolling conditions on sticking behavior. Figure 1 defects on the mill product andscoring on the roll surface. showsthe schematic diagram of the sticking
    [Show full text]
  • Wettability of Aluminium with Sic and Graphite in Aluminium Filtration
    Light Metals 2011 Edited by: Stephen J. Lindsay TMS (The Minerals, Metals & Materials Society), 2011 WETTABILITY OF ALUMINIUM WITH SIC AND GRAPHITE IN ALUMINIUM FILTRATION Sarina Bao1, Anne Kvithyld2, Thorvald Abel Engh1, Merete Tangstad1 Norwegian University of Science and Technology, Trondheim, NO-7491, Norway 2SINTEF Materials and Chemistry, Trondheim, N-7465, Norway Keywords: Wettability, Contact angle, Aluminium, Graphite, SiC, Time dependent property Abstract éõõ The aim of aluminium filtration is to remove inclusions such as ] ■ SCSiC,Laurent,1996 . .nJ ! I · OxidizedSCSiC.Laurent ,1991 AI3C4. For inclusions to be removed they have to come in close '40j-■---;-- £-J.Ì A SSiC,Shimbo,1989 ] T ! : V SSiC,Han,1993 contact with the filter walls composed of A1203 or SiC. It is p I2O1 J.-Ä-..J. : + RBSiC,Han,1993 therefore important that the molten aluminium has close contact ^3 \ ! ! 6 SSiC,Candan,2002 OfHQfll ; ]..►. j I] • SCSiC,Laurent,1987 | with the filter wall. In addition to wetting properties between G J i inclusions (AI4C3) and molten aluminium, the wettability of the s eoi -i i *i i filter (SiC) by aluminium is determined in sessile drop studies in w the temperature range 1000-1300°C. Wettability changes with g 60I-- ! $ 4- time in three successive steps and improves with time. To 40 4 j -.<;- describe wettability at filtration temperatures employed in the Ö I ! industry of around 700°C, the results will be extrapolated to this 2èº ■—.—■—1—-—1—-—i ■—.—■—1—.—I temperature in future work. 600 700 800 900 1000 1100 1200 1300 Introduction Temperature/°C Figure 1 The equilibrium contact angle vs.
    [Show full text]
  • Chemical Compatibility Between Aluminium Base Matrices and Light Refractory Carbide Reinforcements
    CHEMICAL COMPATIBILITY BETWEEN ALUMINIUM BASE MATRICES AND LIGHT REFRACTORY CARBIDE REINFORCEMENTS J.C. Viala, M. Peronnet, F. Bosselet and J. Bouix Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, Université Lyon 1, F 69622 Villeurbanne Cedex, France SUMMARY: The main features of the interface chemistry of Al/B4C, Al/TiC and Al/SiC couples at temperatures up to 1000 °C are presented and discussed in terms of thermodynamics, kinetics and reaction mechanism. The Al/B4C couple appears reactive whatever the temperature whereas a reactive-non reactive transition occurs at 812 °C on heating for the Al/TiC couple and at 650 °C on cooling for the Al/SiC couple. The reaction products are Al3BC and AlB2 or β-AlB12 for the Al/B4C couple, Al4C3 and Al3Ti for Al/TiC and finally Al4C3 and dissolved silicon for Al/SiC. Whatever the couple, interaction always proceeds via a dissolution-precipitation mechanism which ends in certain instances with the passivation of the base carbide surface by a continuous Al3BC or Al4C3 layer. Some examples are given illustrating how advantage can be taken of these features for interface tailoring. KEYWORDS: metal matrix, aluminium, boron carbide, titanium carbide, silicon carbide, interface, chemical reactions. INTRODUCTION The physical and mechanical characteristics of the light refractory carbides SiC, TiC and B4C make them suitable for being used as reinforcement in aluminium base metal matrix composites. Discontinuously reinforced composites or cermets have thus been produced by incorporating particles, small crystals or whiskers of these carbides in the metal matrix by various pyrometallurgic techniques [1-3]. Attempts have also been made to elaborate such products by in-situ reaction of carbon particles with appropriate alloy melts [4, 5].
    [Show full text]
  • Absence of Skin Sensitivity to Oxides of Aluminium, Silicon, Titanium Or Zirconium in Patients With
    Gut1996;39:231-233 231 Absence of skin sensitivity to oxides of aluminium, Silicon, titanium or zirconium in patients with Crohn's disease Gut: first published as 10.1136/gut.39.2.231 on 1 August 1996. Downloaded from J C W Lee, S Halpem, D G Lowe, A Forbes, J E Lennard-Jones Abstract obstructive lymphadenopathy. It has been Background-Some metallic compounds, proposed that this is caused by fibrosis of the especially of zirconium, can cause cell afferent lymphatics as a result of absorption of mediated granulomatous inflammation of microparticles of silica and alumino-silicates the skin. Pigment granules containing through the skin where people walk barefoot compounds of aluminium, silicon, and on certain types of soil. Particles containing titanium have been observed within silica, titanium, and aluminium are present in macrophages in the wall of the small microgranulomata within inguinal lymph intestine in health and in Crohn's disease. nodes of sufferers.6 Granulomata also develop Zirconium compounds can be ingested in in response to intradermal injection ofcolloidal toothpaste. silica in healthy subjects but these are foreign Aim-To determine in a pilot study if body granulomata and are clearly distinguish- granulomatous sensitivity can be detected able from the cell mediated response to small to compounds of these metals or silicon quantities of zirconium lactate.7 after injection into the skin of patients As metals and minerals are ubiquitous in the with Crohn's disease. community, a hypersensitivity to these sub- Subjects-Eight patients with Crohn's stances in some people rather than a direct disease known to have had granulomata in toxic effect is the most probable pathogenetic the intestine and not currently treated mechanism by which they may contribute to with corticosteroids, and two healthy disease.
    [Show full text]
  • Aluminium Carbide
    safety data sheet according to Regulation (EC) No. 1907/2006 (REACH), amended by 2015/830/EU Aluminium carbide pure article number: 3094 date of compilation: 2017-01-17 Version: 1.0 en SECTION 1: Identification of the substance/mixture and of the company/undertaking 1.1 Product identifier Identification of the substance Aluminium carbide Article number 3094 Registration number (REACH) This information is not available. EC number 215-076-2 CAS number 1299-86-1 1.2 Relevant identified uses of the substance or mixture and uses advised against Identified uses: laboratory chemical 1.3 Details of the supplier of the safety data sheet Carl Roth GmbH + Co KG Schoemperlenstr. 3-5 D-76185 Karlsruhe Germany Telephone: +49 (0) 721 - 56 06 0 Telefax: +49 (0) 721 - 56 06 149 e-mail: [email protected] Website: www.carlroth.de Competent person responsible for the safety data : Department Health, Safety and Environment sheet e-mail (competent person) : [email protected] 1.4 Emergency telephone number Emergency information service Poison Centre Munich: +49/(0)89 19240 SECTION 2: Hazards identification 2.1 Classification of the substance or mixture Classification according to Regulation (EC) No 1272/2008 (CLP) Classification acc. to GHS Section Hazard class Hazard class and cat- Hazard egory state- ment 2.12 substance and mixture which, in contact with water, emits flam- (Water-react. 2) H261 mable gas 3.2 skin corrosion/irritation (Skin Irrit. 2) H315 3.3 serious eye damage/eye irritation (Eye Irrit. 2) H319 3.8R specific target organ toxicity - single exposure (respiratory tract ir- (STOT SE 3) H335 ritation) Ireland (en) Page 1 / 12 safety data sheet according to Regulation (EC) No.
    [Show full text]
  • H-Shaped Steel Manufacturing Technology
    NIPPON STEEL & SUMITOMO METAL TECHNICAL REPORT No. 111 MARCH 2016 Technical Report UDC 621 . 771 . 261 - 423 . 1 H-shaped Steel Manufacturing Technology Eiji SAIKI* Katsuya MATSUDA Abstract The outline of the H-shaped steel manufacturing technologies of Nippon Steel & Sumitomo Metal Corporation is introduced. Compared with the conventional technologies of manufactur- ing general H-shaped steel, the technologies introduced here are characterized by four features for producing H-shaped steel of various dimensions with high efficiency. The features enable the production of H-shaped steel having (1) different web height dimensions without any sig- nificant difficulty using a pair of skewed rolls and free size finishing rolls (barrel-length adjust- able finishing rolls), (2) high flange/web thickness ratio using rolling temperature control tech- nology, (3) different flange width without changing edging rolls using free-size edging rolls (caliber-depth adjustable edging rolls), and (4) enable production of a variety of sizes of H- shaped steel from a single rectangular cross-sectional material using sizing rolling technology. 1. Introduction exists a limit in the size range of producible H-shaped steel because The conventional rolling method of H-shaped steel comprises of internal stress caused by the temperature difference within a sec- the process of, as shown in Fig. 1, shaping a material heated in a re- tion developed by a difference in the transition of temperature dur- heating furnace to a beam blank shape by a roughing mill, shaping ing rolling, which causes web buckling when it grows excessively to the final product size by reducing the flange and web thicknesses large.
    [Show full text]