DOCSLIB.ORG

Corrosion of Hafnium and Hafnium Alloys

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Corrosion of Hafnium and Hafnium Alloys © 2005 ASM International. All Rights Reserved. www.asminternational.org ASM Handbook, Volume 13B, Corrosion: Materials (#06508G) Corrosion of Hafnium and Hafnium Alloys D.R. Holmes, ATI Wah Chang, Allegheny Technologies HAFNIUM is element number 72. It resides in In addition to the inherent corrosion resistance impurities such as oxygen, carbon, and nitrogen group IVA of the periodic table with titanium of hafnium, other properties make hafnium use- are left behind, along with some of the impurity and zirconium. Hafnium is always associated ful in chemical equipment. It is relatively easy to metals. Electron beam melting is also effective in with zirconium in minerals such as zircon and form and join, sufficiently strong, ductile, and purifying hafnium. In this process, hafnium is baddeleyite, usually in the range of 1 to 5%. wear resistant to withstand the abuse of industrial slowly double-melted under high vacuum. This The chemical similarity between hafnium and applications. Its coefficient of thermal expansion process removes impurities having partial pres- zirconium is more pronounced than between any is approximately 60% lower than that of 304 sures at the surface of the melt greater than the other two elements in the periodic table, except stainless steel at ambient temperature, and its vapor pressure of hafnium, which is approxi- the inert gases. This similarity in chemistry of thermal conductivity is approximately 40% mately 0.1 Pa (0.75 mm Hg) at 2500 K hafnium and zirconium makes separation ex- higher at ambient temperature (Ref 3). (4040 F). The more volatile metallic impurities, tremely difficult. Along with zirconium, hafnium Hafnium appears to be nontoxic. Haygarth such as iron, manganese, and aluminum, along forms intermetallic compounds with most and Graham state that “there seems to be no with chlorine, are moved. Only the higher- metallic elements, except the alkali metals and report of the metal, or its alloys with nontoxic melting-point metals, such as tantalum and some alkaline earths (Ref 1). Hafnium is constituents, causing physiological reaction” tungsten, are not removed. To get the highest obtained as a by-product of the extraction pro- (Ref 3). Like zirconium, dissolved hafnium ions purity possible, the van Arkel-de Boer process cess to produce hafnium-free nuclear-grade zir- are colorless—an important attribute for some and electron beam melting are used in sequence. conium. Commercial hafnium typically contains applications. The United States Government allows the 0.2 to 4.5% Zr. The van Arkel-de Boer (iodine) export of high-hafnium (0.2% or greater) process is used to obtain hafnium purities of commercial-grade (nonnuclear) zirconium greater than 99.99%. Annual world consumption Production (UNS R60702) to most countries. This level of of hafnium was approximately 60 tons in 2003 hafnium content prevents commercial-grade (Ref 2). Because hafnium is always associated with zirconium from being modified for use in nuclear Hafnium was first identified by x-ray analysis zirconium, two main processes have been used to production facilities. This requirement limits the in 1923 by Coster and von Hevesy in Copenha- separate hafnium from zirconium. A European amount of hafnium metal available for other gen, Denmark. Von Hevesey and Jantzen were producer uses an extractive distillation process, uses. the first to separate hafnium from zirconium by while in the United States a liquid-liquid repeated recrystallization of fluoride salts. The extraction is the preferred method. Two primary name hafnium comes from the Latin name for operational methods of metal production are also Physical and Mechanical Properties Copenhagen, which is Hafnia. Van Arkel and de possible. The Kroll process is the primary of Hafnium Boer were the first to produce metallic hafnium. reduction process used in the United States, Their process of passing hafnium tetraiodide while in Europe an electrowinning process is Hafnium is often considered for the same vapor over a heated filament is the basis for the preferred. Ullman gives a detailed description for applications as zirconium, because of their very refining process used today to produce higher- each of these processes (Ref 4). similar physical and chemical characteristics. In purity hafnium metal. Highest-purity metal is obtained by using the fact, Clark (Ref 1) states that other than the With a standard reduction potential of van Arkel-de Boer process, also known as the higher transition temperatures (a!b) for haf- À1.72 V versus the normal hydrogen electrode iodine bar or crystal bar process. In this process, nium, the only other chemical and physical at 24 C (75 F), hafnium is more reactive hafnium sponge produced by the Kroll process is property showing a major difference between than either titanium (À1.63 V) or zirconium loaded into a cylindrical Ni-Cr-Fe vessel. The these elements is the density. Both zirconium and (À1.53 V). This high chemical reactivity allows vessel lid contains insulated electrical lines from hafnium exhibit anisotropy; their mechanical a thin, tenacious protective oxide layer to form which a hafnium wire filament, in a hairpin properties depend on the direction in which they when exposed to most chemical environ- shape, is suspended. Iodine is added to the vessel, are measured. Table 1 gives the physical prop- ments. Like other reactive metals, hafnium which is then evacuated and heated to vaporize erties of hafnium, while Table 2 gives the resists attack by many chemicals as long as the iodine. Volatile hafnium tetraiodide forms mechanical properties. this thin oxide layer is not penetrated by reac- and diffuses to the central hafnium filament, Chemical Properties. The ionic radii of tants. Oxide layers can also be developed by which is resistance heated to 1200 to 1500 C zirconium and hafnium are almost identical, anodizing and by treatment in steam autoclaves (2200 to 2700 F). The tetraiodide thermally due to the lanthanide contraction. This results and in air at elevated temperatures. The most dissociates at the hot filament, depositing haf- in very similar chemical properties between commonly formed oxide is hafnium dioxide nium and releasing iodine to react again with the the two metals. As a result, a review of the (HfO2). Because of its high melting point of sponge feed. This cycle continues until the effi- chemical behavior of zirconium can be a use- 2222 C (4032 F), hafnium may be considered ciency diminishes (Ref 4, 5). Under conditions ful indicator of the chemical behavior of refractory. optimized for hafnium transfer, interstitial hafnium (Ref 4). © 2005 ASM International. All Rights Reserved. www.asminternational.org ASM Handbook, Volume 13B, Corrosion: Materials (#06508G) 2 / Corrosion of Nonferrous Alloys and Specialty Products Table 1 Physical properties of hafnium Specifications and Standards. Hafnium removes other surface imperfections where pit- comes in two grades: grade R1 for nuclear ting may be initiated. Pickling hafnium requires Property Value applications (low zirconium) and grade R3 for a solution of 3 to 7% hydrofluoric acid (48% Atomic number 72 commercial applications and alloying. Higher- concentration) with 25 to 59% nitric acid (70% Atomic weight 178.49 Density, kg/m3 (lb/in.3) 13.31 · 103 (0.481) quality material can be produced by the crystal concentration) and the balance of water. Heat Modulus of elasticity, MPa (ksi) bar process. Grade R3 hafnium is available in treatment for weldments may also be beneficial At 294 K (70 F) 13.7 · 104 (2.00 · 104) specific grades from 0.5 to 4.5% Zr content (Ref for corrosion resistance in specific applications. 4 4 At 533 K (500 F) 10.6 · 10 (1.54 · 10 ) 6). No Unified Numbering System number has Heat treatments may be either a solution anneal At 644 K (700 F) 9.5 · 104 (1.38 · 104) Magnetic susceptibility per g at 0.42 · 10À6 been assigned to hafnium. ASTM B 776, requiring high temperatures or a stress anneal at 298.2 K (77.4 F) “Standard Specification for Hafnium and Haf- lower temperatures. The choice of heat treatment Hall effect at 25 C (77 F), À1.62 · 10À12 nium Alloy Strip, Sheet, and Plate” (Ref 7), depends on the specific environment and appli- Vm/AT includes chemistry requirements. Table 3 gives cation. Spectral emissivity, 0.40 the chemical composition of three grades of For corrosion tests involving stress-corrosion 1750–2300, e0.65u Electron emission, A/m2 hafnium. or environmental cracking, such as tensile, U- At 1900 K (2960 F) 4.80 · 10 bend, or C-ring specimens, consideration should 2 At 2000 K (3140 F) 2.62 · 10 be given to the anisotropy in hafnium. Specimen At 2100 K (3320 F) 1.23 · 103 At 2200 K (3500 F) 4.85 · 103 Aqueous Corrosion Testing of properties such as thermal expansion, yield Work function, J 6.25 · 10À19 Hafnium and Hafnium Alloys strength, tensile elongation, and bend ductility Thermal neutron absorption 104 depend on the orientation of mill products. cross section, barns Anisotropy is a characteristic of zirconium, Crystal structure It is not the purpose of this article to describe titanium, and hafnium but not of niobium or Alpha phase Hexagonal close-packed the recommended procedure for corrosion tantalum. Table 2 gives examples of changes in Beta phase Body-centered cubic testing. Reactive-metals corrosion testing, spe- Alpha-to-beta transformation 2033 (3200) mechanical properties between materials tested cifically zirconium and hafnium, is, however, temperature, K ( F) in the longitudinal and transverse directions. Melting point, K (F) 2500 (4041) sufficiently different from stainless steels, Welding of reactive metals for corrosion Boiling point, K ( F) 4875 (8312) nickel-base alloys, and more common materials · À6 samples also requires some care. Although Coefficient of linear thermal 5.9 10 of construction to warrant a few comments. expansion, (m/m)/K, commonly welded, hafnium and other reactive Testing procedure ASTM G 2, “Corrosion at 273–1273 K (32–1830 F) metals are very sensitive to contamination by Thermal conductivity, W/m Á K Testing of Products of Zirconium, Hafnium and oxygen, nitrogen, hydrogen, and carbon during At 298 K (77 F) 23 Their Alloys in Water at 360 C (680 F) or the welding process.
Load more

Recommended publications
  • Lanthanides & Actinides Notes
    - 1 - LANTHANIDES & ACTINIDES NOTES General Background Mnemonics Lanthanides Lanthanide Chemistry Presents No Problems Since Everyone Goes To Doctor Heyes' Excruciatingly Thorough Yearly Lectures La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Actinides Although Theorists Prefer Unusual New Proofs Able Chemists Believe Careful Experiments Find More New Laws Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Principal Characteristics of the Rare Earth Elements 1. Occur together in nature, in minerals, e.g. monazite (a mixed rare earth phosphate). 2. Very similar chemical properties. Found combined with non-metals largely in the 3+ oxidation state, with little tendency to variable valence. 3. Small difference in solubility / complex formation etc. of M3+ are due to size effects. Traversing the series r(M3+) steadily decreases – the lanthanide contraction. Difficult to separate and differentiate, e.g. in 1911 James performed 15000 recrystallisations to get pure Tm(BrO3)3! f-Orbitals The Effective Electron Potential: • Large angular momentum for an f-orbital (l = 3). • Large centrifugal potential tends to keep the electron away from the nucleus. o Aufbau order. • Increased Z increases Coulombic attraction to a larger extent for smaller n due to a proportionately greater change in Zeff. o Reasserts Hydrogenic order. This can be viewed empirically as due to differing penetration effects. Radial Wavefunctions Pn,l2 for 4f, 5d, 6s in Ce 4f orbitals (and the atoms in general) steadily contract across the lanthanide series. Effective electron potential for the excited states of Ba {[Xe] 6s 4f} & La {[Xe] 6s 5d 4f} show a sudden change in the broadness & depth of the 4f "inner well".
    [Show full text]
  • Download Article (PDF)
    Recent IUPAC technical reports and recommendations that aff ect the many fi elds of pure and applied chemistry. Making an imPACt See also www.iupac.org/what-we-do/journals/ Standard Atomic Weight of Hafnium elements. For example, radioactive decay of lutetium Revised alters the isotopic composition of hafnium by produc- ing the light isotope of hafnium-176. Thus, some rare The IUPAC Com- terrestrial materials can have abnormal isotopic com- mission on Isotopic positions of hafnium with the most extreme known Abundances and case being sedimentary chert from South Africa hav- Atomic Weights ing atomic-weight value of 178.447. (CIAAW) met under The CIAAW continues to evaluate literature data the chairmanship of which leads to identifi cation of developments in the Dr. Juris Meija (Can- measurement science, recognition of new discover- ada), at the Federal ies, and remains committed to modernize its technical Institute for Mate- guidelines and work towards further expansion of its rials Research and website to include more historical databases. These Testing (bam.de), changes and considerations will be published in Pure Berlin Germany, in and Applied Chemistry [2] and can be found online at June 2019. As IUPAC celebrates its centennial in 2019, the website of The CIAAW (ciaaw.org). its oldest body, the CIAAW, turns 120 with its beginnings tracing back to Berlin in 1899 [1]. Following its 2019 Notes meeting, the CIAAW recommended changes to the stan- 1. For a historical account of the CIAAW, see J.R. De dard atomic weight (i.e. relative atomic mass) of hafnium Laeter and J.
    [Show full text]
  • The Development of the Periodic Table and Its Consequences Citation: J
    Firenze University Press www.fupress.com/substantia The Development of the Periodic Table and its Consequences Citation: J. Emsley (2019) The Devel- opment of the Periodic Table and its Consequences. Substantia 3(2) Suppl. 5: 15-27. doi: 10.13128/Substantia-297 John Emsley Copyright: © 2019 J. Emsley. This is Alameda Lodge, 23a Alameda Road, Ampthill, MK45 2LA, UK an open access, peer-reviewed article E-mail: [email protected] published by Firenze University Press (http://www.fupress.com/substantia) and distributed under the terms of the Abstract. Chemistry is fortunate among the sciences in having an icon that is instant- Creative Commons Attribution License, ly recognisable around the world: the periodic table. The United Nations has deemed which permits unrestricted use, distri- 2019 to be the International Year of the Periodic Table, in commemoration of the 150th bution, and reproduction in any medi- anniversary of the first paper in which it appeared. That had been written by a Russian um, provided the original author and chemist, Dmitri Mendeleev, and was published in May 1869. Since then, there have source are credited. been many versions of the table, but one format has come to be the most widely used Data Availability Statement: All rel- and is to be seen everywhere. The route to this preferred form of the table makes an evant data are within the paper and its interesting story. Supporting Information files. Keywords. Periodic table, Mendeleev, Newlands, Deming, Seaborg. Competing Interests: The Author(s) declare(s) no conflict of interest. INTRODUCTION There are hundreds of periodic tables but the one that is widely repro- duced has the approval of the International Union of Pure and Applied Chemistry (IUPAC) and is shown in Fig.1.
    [Show full text]
  • Growth and Characterization of Lif Single-Crystal Fibers by the Micro
    ARTICLE IN PRESS Journal of Crystal Growth 270 (2004) 121–123 Growth and characterization of LiF single-crystal fibers by the micro-pulling-down method A.M.E. Santoa, B.M. Epelbaumb, S.P. Moratoc, N.D. Vieira Jr.a, S.L. Baldochia,* a Instituto de Pesquisas Energeticas! e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, CEP 05508-900, Sao* Paulo, SP, Brazil b Department of Materials Science, University of Erlangen-Nurnberg, D-91058, Erlangen, Germany c LaserTools Tecnologia Ltda., 05379-130,Sao* Paulo, SP, Brazil Accepted 27 May 2004 Available online 20 July 2004 Communicated by G. Muller. Abstract Good optical quality LiF single-crystalline fibers ranging from 0:5to0:8 mm in diameter and 100 mm in length were successfully grown by the micro-pulling-down technique in the resistive mode. A commercial equipment was modified in order to achieve suitable conditions to grow fluoride single-crystalline fibers. r 2004 Elsevier B.V. All rights reserved. PACS: 81.10.Fq; 78.20.Àe Keywords: A2. Micro-pulling-down method; A2. Single crystal growth; B1. Fluorides 1. Introduction oxide single-crystals have already been grown by the laser heated pedestal growth (LHPG) [2] and There is an increasinginterest in the production by the micro-pulling-down (m-PD) [3] methods. of single-crystalline fibers. Their unique properties However, the growth and hence the possible indicate their use for production of a variety of applications of fluoride single-crystalline fibers optical and electronic devices [1]. The final shape has not yet been investigated. of the single-crystalline fiber is already in a form As it is already known from other methods of suitable for optical testingand applications, fluoride growth, these materials are very sensitive reducingthe time and cost of preparation.
    [Show full text]
  • Electronic Structure of Ytterbium(III) Solvates – a Combined Spectro
    Electronic Structure of Ytterbium( III) Solvates – A Combined Spectro- scopic and Theoretical Study Nicolaj Kofod,† Patrick Nawrocki,† Carlos Platas-Iglesias,*,‡ Thomas Just Sørensen*,† † Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Den- mark. ‡ Centro de Investigacións Científicas Avanzadas and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain ABSTRACT: The wide range of optical and magnetic properties of the lanthanide(III) ions is associated to their intricate electronic structures, which in contrast to lighter elements is characterized by strong relativistic effects and spin-orbit coupling. Nevertheless, computational methods are now capable of describing the ladder of electronic energy levels of the simpler trivalent lanthanide ions, as well as the lowest energy term of most of the series. The electronic energy levels result from electron configurations that are first split by spin-orbit coupling into groups of energy levels denoted by the corresponding Russel-Saunders terms. Each of these groups are then split by the ligand field into the actual electronic energy levels known as microstates or sometimes mJ levels. The ligand field splitting directly informs on coordination geometry, and is a valuable tool for determining structure and thus correlating the structure and properties of metal complexes in solution. The issue with lanthanide com- plexes is that the determination of complex structures from ligand field splitting remains a very challenging task. In this manuscript, the optical spectra – absorption, luminescence excitation and luminescence emission – of ytterbium(III) solvates were recorded in water, methanol, dime- thyl sulfoxide and N,N-dimethylformamide.
    [Show full text]
  • Why Isn't Hafnium a Noble Gas? Also More on the Lanthanide Contraction
    return to updates Period 6 Why Isn't Hafnium a Noble Gas? also more on the Lanthanide contraction by Miles Mathis First published March 30, 2014 This paper replaces my earlier paper on the Lanthanides After a long break, it is time I returned to the Periodic Table. Many readers probably wish I would concentrate more on one subject, or at least one area of physics or chemistry. Possibly, they think I would get more done that way. They are mistaken. I would indeed get more done in that one field, and if that is their field, of course that would satisfy them more personally. But by skipping around, I actually maximize my production. How? One, I stay fresh. I don't get bored by staying in one place too long, so my creativity stays at a peak. Two, I cross-pollinate my ideas. My readers have seen how often a discovery in one sub-field helps me in another sub-field, even when those two fields aren't adjacent. All of science (and life) is ultimately of a piece, so anything I learn anywhere will help me everywhere else. Three, being interested in a wide array of topics gives me a bigger net, and with a bigger net I am better able to capture solutions across the board. Knowledge isn't just a matter of depth, it is a matter of breadth. In philosophy classes, we were taught this as part of the hermeneutic circle: the parts feed the whole and the whole feeds back into all the parts.
    [Show full text]
  • Introduction to Corrosion Your Friendly TSC Corrosion Staff
    Introduction to Corrosion Your Friendly TSC Corrosion Staff: Daryl Little Ph.D. Materials Science & Engineering [email protected] 303-445-2384 Lee Sears Ph.D. Materials Science & Engineering [email protected] 303-445-2392 Jessica Torrey Ph.D. Materials Science & Engineering [email protected] 303-445-2376 Roger Turcotte, PE, CPS Materials Engineer [email protected] 303-445-2383 What is Corrosion? CORROSION IS DEFINED AS THE DETERIORATION OF A MATERIAL AND/OR ITS PROPERTIES CAUSED BY A REACTION WITH ITS ENVIRONMENT. Why is Corrosion a Major Concern? First and Most Important- Public Safety! • June 28, 1983: Mianus River Bridge, Greenwich, CT (TIME photo archive) • Northbound 3-lane section of I-95 bridge collapsed, killing 3 people • “Pin and Hanger” design was compromised when pin was displaced due to extensive corrosion of load-bearing components, amplified by salt from road maintenance. • Inadequate maintenance procedures were also cited as a contributing factor. • Subsequent to this failure, extensive inspections were conducted on this type of bridge across the country, and design modification were made to prevent catastrophic failures of this kind. First and Most Important- Public Safety! • April 28,1988, Aloha Airlines 737 Accident • 18 feet of cabin skin ripped off, resulting in the death of a flight attendant and many injuries • Attributed to corrosion fatigue Reclamation Case Study- Folsom Dam • Spillway gate No. 3 was damaged beyond repair, but no flooding occurred. • Replacement of No. 3 and repair of other gates cost ~$20 million and required 40% drainage of reservoir • Cause of failure: Increasing corrosion at the trunnion pin-hub interface raised the coefficient of friction and, therefore, the bending stress in the strut and the axial force in the brace exceeded limits.
    [Show full text]
  • Of the Periodic Table
    of the Periodic Table teacher notes Give your students a visual introduction to the families of the periodic table! This product includes eight mini- posters, one for each of the element families on the main group of the periodic table: Alkali Metals, Alkaline Earth Metals, Boron/Aluminum Group (Icosagens), Carbon Group (Crystallogens), Nitrogen Group (Pnictogens), Oxygen Group (Chalcogens), Halogens, and Noble Gases. The mini-posters give overview information about the family as well as a visual of where on the periodic table the family is located and a diagram of an atom of that family highlighting the number of valence electrons. Also included is the student packet, which is broken into the eight families and asks for specific information that students will find on the mini-posters. The students are also directed to color each family with a specific color on the blank graphic organizer at the end of their packet and they go to the fantastic interactive table at www.periodictable.com to learn even more about the elements in each family. Furthermore, there is a section for students to conduct their own research on the element of hydrogen, which does not belong to a family. When I use this activity, I print two of each mini-poster in color (pages 8 through 15 of this file), laminate them, and lay them on a big table. I have students work in partners to read about each family, one at a time, and complete that section of the student packet (pages 16 through 21 of this file). When they finish, they bring the mini-poster back to the table for another group to use.
    [Show full text]
  • The Corrosion of Iron and Its Alloys
    UNIVERSITY OF ILLINOIS LIBRARY Class Book Volume ^ M rlO-20M -r - 4 'f . # f- f f > # 4 Tjh- |fe ^ lINlN^ ' ^ ^ ^* 4 if i i if i^M^'M^i^ H II I li H : : \ ; . tNP* i rHt . ; ^ * 41 W 4s T »f 4 ^ -f 4. f -4- * i 4 4 : * 1- 1 4 % 3**:- ->^> A 4- - 4- + * ,,4 * 4" T '* * 4 -f- ± f * * 4- 4 -i * 4 ^ 4* -f + > * * + 1 f * 4 # * .-j* * + * ^ £ - jjR ^^MKlF^ f ^ f- + f v * IT :/^rV :,HH':,* ^ 4 * ^ 4 -f- «f f 4- 4 4 ,,rSK|M| ; * 4 # ; || II I II II f || .- -fr 4* , «g* 4 I. ^ vmiM 4- THE CORROSION OF IRON AND ITS ALLOYS BY RUSSELL SAMUEL HOWARD THESIS FOR THE DEGREE OF BACHELOR OF SCIENCE IN CHEMISTRY IN THE COLLEGE OF SCIENCE OF THE UNIVERSITY OF ILLINOIS Presented June, 1910 UNIVERSITY OF ILLINOIS June 1 1910 THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Russel Samuel Howard ENTITLED The Corrosion of Iron and It s Alloys IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE OF Bachelor of Scienc e In Chemistry Instructor in Charge Approved: HEAD OF DEPARTMENT OF 167529 Digitized by the Internet Archive in 2013 ^ttp://archive.org/details/corrosionofironiOOhowa CORROSION OF IRON AND ITS ALLOYS. In nature everything is subject to deterioration, varying from those substances decomposed by light to those only decomposed by the strong- est agents. The deterioration of metals as effected by alloying is the sub- ject of this paper and perhaps .no subject is of more vital importance to the builder and interest to the chemist than this one of corrosion.
    [Show full text]
  • INFLUENCE of Ph on the LOCALIZED CORROSION of IRON
    BNL 39687 MIT/BNL-86-6 INFORMAL REPORT INFLUENCE OF pH ON THE LOCALIZED CORROSION OF IRON MIT/BNL-86-6 BNL—39687 DE87 010452 R. Webley and R. Henry Consultants: H. Isaacs and G. Cragnolino June 1986 BROOKHAVEN STATION SCHOOL OF CHEMICAL ENGINEERING PRACTICE MASSACHUSETTS INSTITUTE OF TECHNOLOGY R.O. SPROULL. DIRECTOR F.J. HRACH, ASSISTANT DIRECTOR DEPARTMENT OF APPLIED SCIENCE BROOKHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES. INC. UPTON, LONG ISLAND, NEW YORK 11973 UNDER CONTRACT NO. DE-AC02-76CH00016 WITH THE UNITED STATES DEPARTMENT OF ENERGY MASTER DISTRIBUTION OF TMiS DOCUMENT IS UNLIMITED DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontrac- tors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or use- fulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency, contractor or subcontractor thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency, contractor or subcontractor thereof. ABSTRACT The influence of pH on the pitting corrosion of iron in chloride and sul- fate solutions was determined using two artificial pit apparatuses to obtain the pH near the surface of the pit bottom.
    [Show full text]
  • Radiochemistry of Zirconium and Niobium
    .... I 5+1 ,.. S8J9P cd ,.. R.ADIOCHEFUX3TRYOF Z=COM,~ AND HIOBIUM BY Ei,liFJ:P. Steinberg RADIOCHEHISTRYOF ZIRCONIUMAND NIOBI~ Table of Contents ——— .. ,. ., Page Zirconium. ..g . ...* .,* 1 .,* 5 Solvent ExtraotlonPrmedure for Zr . ● *. 9 Zirconium Procedure . ● . ● .12 ~~ NloblumProaedure. preparationof’Carrier-FreeZr Traoer . , 24 preparationof Carrier-~ee zr-~ ~aw= . ● ● . ● . - . 26 Improved Preparationof Camier-Free Mb Traaer with ● m9 30 mlo2 RWUWHEMISTRY OF Z~CWUUM MB HIOBIUVl by Ellis P. Stetnberg (Based largely on an wqmbltshed review by D. M. Hume) Zmm!?rfm Macro Chemistry The only importantoxldatio~number Is +4. The normal state in aqueous sel.uttonts the ztreomyl ion (ZrC$~);the tetrapositlvaion Is net capable of existenceIn dilute acid solutions. Alkall hydroxides and ~nia precipitatezlrconyl salts as ZrO(OH)2, insolubleIn excess base but soluble In mineral aeide. The precipitationis hi~dered by mu@h ammonium \ fluoride...On~eat@g or drying, the hydroxide is converted to the muoh more oxide is soluble only In hy@w3$lu6@e acid. I@lrogen sulfide has no effeot on ,sQlutlonsof’zirconiumsalts. Alkali sulfides ,~eoipitatebhe kq~xide. zireQnyl ni~rate, chloride,and sulf’ateare sol,uble,ln aoid solution. Zircwayl fluoride is Znsolublek@ readily dis.eolvesin k@rdlu@rie add. Reduetlom ,, ,, to the metal”is very dif’flcult.Uommeroialzirconiumecmtains an appreciableamun’k of’-iwz,impurity. Among the..mere Wportant insoluble oompmnds is the very -18 tBtic@blephosphate,Zm(H@04) ~, Kap = 2●28 x 10 which 2 precipitateseven 20$ sulfurioaoid. It has properties from .. similar to those of cerlc phosphatebut is dissolvedby hydro- fluoric acid. The iodate preolpttatesfrom 8 g HN03 and the aryl-substitutedarsenatesand oupferrtdeprecipitatefrom acid solutions;none are appreciablysoluble in excess reagent.
    [Show full text]
  • Surface Chemistry of Zirconium
    Progress in Surface Science 78 (2005) 101–184 www.elsevier.com/locate/progsurf Review Surface chemistry of zirconium N. Stojilovic, E.T. Bender, R.D. Ramsier * Departments of Physics and Chemistry, The University of Akron, 250 Buchtel Commons, Ayer Hall 111, Akron, OH 44325-4001, USA Abstract This article presents an overview of the surface chemistry of zirconium, focusingon the relationship of what is known from model studies and how this connects to current and future applications of Zr-based materials. The discussion includes the synergistic nature of adsorbate interactions in this system, the role of impurities and alloyingelements, and temperature- dependent surface–subsurface transport. Finally, some potential uses of zirconium and its alloys for biomedical and nanolithographic applications are presented. Ó 2005 Elsevier Ltd. All rights reserved. Keywords: Zirconium; Oxidation; Surface chemistry; Subsurface species; Diffusion; Water; Oxygen; Hydrogen; Nuclear materials; Alloys; Zircaloy Contents 1. Contextual overview........................................ 102 2. Systems of interest ......................................... 104 2.1. Water ............................................. 104 2.2. Oxygen ............................................ 122 2.3. Hydrogen .......................................... 132 2.4. Sulfur ............................................. 143 2.5. Carbon ............................................ 147 * Correspondingauthor. Tel.: +1 330 9724936; fax: +1 330 9726918. E-mail address: [email protected] (R.D.
    [Show full text]