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Chromium properties

Chromium(III) hydroxide, like aluminium hydroxide, possesses adsorptive power, and the use of ehromium compounds as mordants is due to this property. [Pg.382]

The metal has unusual superconductive properties. As little as 1 percent gadolinium improves the workability and resistance of iron, chromium, and related alloys to high temperatures and oxidation. [Pg.188]

Rocha, E. R. P. Nobrega, J. A. Effects of Solution Physical Properties on Copper and Chromium Signals in Plame Atomic Absorption Spectrometry, /. Chem. Educ. 1996, 73, 982-984. [Pg.449]

Chemical ingenuity in using the properties of the elements and their compounds has allowed analyses to be carried out by processes analogous to the generation of hydrides. Osmium tetroxide is very volatile and can be formed easily by oxidation of osmium compounds. Some metals form volatile acetylacetonates (acac), such as iron, zinc, cobalt, chromium, and manganese (Figure 15.4). Iodides can be oxidized easily to iodine (another volatile element in itself), and carbonates or bicarbonates can be examined as COj after reaction with acid. [Pg.100]

Common alloying elements include nickel to improve low temperature mechanical properties chromium, molybdenum, and vanadium to improve elevated-temperature properties and silicon to improve properties at ordinary temperatures. Low alloy steels ate not used where corrosion is a prime factor and are usually considered separately from stainless steels. [Pg.347]

Carbon content is usually about 0.15% but may be higher in bolting steels and hot-work die steels. Molybdenum content is usually between 0.5 and 1.5% it increases creep—mpture strength and prevents temper embrittlement at the higher chromium contents. In the modified steels, siUcon is added to improve oxidation resistance, titanium and vanadium to stabilize the carbides to higher temperatures, and nickel to reduce notch sensitivity. Most of the chromium—molybdenum steels are used in the aimealed or in the normalized and tempered condition some of the modified grades have better properties in the quench and tempered condition. [Pg.117]

Ferritic stainless steels depend on chromium for high temperature corrosion resistance. A Cr202 scale may form on an alloy above 600°C when the chromium content is ca 13 wt % (36,37). This scale has excellent protective properties and occurs iu the form of a very thin layer containing up to 2 wt % iron. At chromium contents above 19 wt % the metal loss owiag to oxidation at 950°C is quite small. Such alloys also are quite resistant to attack by water vapor at 600°C (38). Isothermal oxidation resistance for some ferritic stainless steels has been reported after 10,000 h at 815°C (39). Grades 410 and 430, with 11.5—13.5 wt % Cr and 14—18 wt % Cr, respectively, behaved significandy better than type 409 which has a chromium content of 11 wt %. [Pg.118]

Chromium—Cobalt—Iron Alloys. In 1971, a family of ductile Cr—Co—Fe permanent-magnet alloys was developed (79). The Cr—Co—Fe alloys are analogous to the Alnicos in metallurgical stmcture and in permanent magnetic properties, but are cold formable at room temperature. Equivalent magnetic properties also can be attained with substantially less Co, thereby offering savings in materials cost. [Pg.383]

Physical Properties. Molybdenum has many unique properties, leading to its importance as a refractory metal (see Refractories). Molybdenum, atomic no. 42, is in Group 6 (VIB) of the Periodic Table between chromium and tungsten vertically and niobium and technetium horizontally. It has a silvery gray appearance. The most stable valence states are +6, +4, and 0 lower, less stable valence states are +5, +3, and +2. [Pg.463]

Nickel—Iron. A large amount of nickel is used in alloy and stainless steels and in cast irons. Nickel is added to ferritic alloy steels to increase the hardenabihty and to modify ferrite and cementite properties and morphologies, and thus to improve the strength, toughness, and ductihty of the steel. In austenitic stainless steels, the nickel content is 7—35 wt %. Its primary roles are to stabilize the ductile austenite stmcture and to provide, in conjunction with chromium, good corrosion resistance. Nickel is added to cast irons to improve strength and toughness. [Pg.6]

Another anomalous property of some nickel—iron aHoys, which are caHed constant-modulus aHoys, is a positive thermoelastic coefficient which occurs in aHoys having 27—43 wt % nickel. The elastic moduH in these aHoys increase with temperature. UsuaHy, and with additions of chromium, molybdenum, titanium, or aluminum, the constant-modulus aHoys are used in precision weighing machines, measuring devices, and osciHating mechanisms (see Weighing AND proportioning). [Pg.6]

Processes for HDPE with Broad MWD. Synthesis of HDPE with a relatively high molecular weight and a very broad MWD (broader than that of HDPE prepared with chromium oxide catalysts) can be achieved by two separate approaches. The first is to use mixed catalysts containing two types of active centers with widely different properties (50—55) the second is to employ two or more polymerization reactors in a series. In the second approach, polymerization conditions in each reactor are set drastically differendy in order to produce, within each polymer particle, an essential mixture of macromolecules with vasdy different molecular weights. Special plants, both slurry and gas-phase, can produce such resins (74,91—94). [Pg.387]

Al—Cr. Although no commercial ahoys are based on this system, chromium [7440-47-3] Cr, is an ingredient of several complex and commercially significant ahoys (Fig. 16. The Cr is added for control of grain stmcture. The Al—Cr system has a peritectic portion at 661°C where soHd solubiHty is 0.7% Cr and Hquid solubiHty is 0.4% Cr. Free2ing of binary ahoys containing >0.4% Cr produces coarse primary crystals (metallic inclusions) of AlyCr [12005-37-7] which may adversely affect mechanical properties. In complex ahoys, the Hquid solubiHty can be reduced such that formation of primary AlyCr crystals may occur at significantly lower Cr contents. [Pg.113]

Vitahium FHS ahoy is a cobalt—chromium—molybdenum ahoy having a high modulus of elasticity. This ahoy is also a preferred material. When combiaed with a properly designed stem, the properties of this ahoy provide protection for the cement mantle by decreasing proximal cement stress. This ahoy also exhibits high yields and tensile strength, is corrosion resistant, and biocompatible. Composites used ia orthopedics include carbon—carbon, carbon—epoxy, hydroxyapatite, ceramics, etc. [Pg.190]

The physical and mechanical properties of steel depend on its microstmcture, that is, the nature, distribution, and amounts of its metaHographic constituents as distinct from its chemical composition. The amount and distribution of iron and iron carbide determine most of the properties, although most plain carbon steels also contain manganese, siUcon, phosphoms, sulfur, oxygen, and traces of nitrogen, hydrogen, and other chemical elements such as aluminum and copper. These elements may modify, to a certain extent, the main effects of iron and iron carbide, but the influence of iron carbide always predominates. This is tme even of medium alloy steels, which may contain considerable amounts of nickel, chromium, and molybdenum. [Pg.384]

Physical and Chemical Properties. Titanium dioxide [13463-67-7] occurs in nature in three crystalline forms anatase [1317-70-0] brookite [12188-41 -9] and mtile [1317-80-2]. These crystals are essentially pure titanium dioxide but contain small amounts of impurities, such as iron, chromium, or vanadium, which darken them. Rutile is the thermodynamically stable form at all temperatures and is one of the two most important ores of titanium. [Pg.120]

Chromium complexes of long-chain fatty acids are exceUent water repeUents which are also used for their food-release properties in certain packaging appHcations. The presence of chromium has raised environmental concerns, despite the fact that the metal is in the trivalent rather than in the highly toxic hexavalent state. This material is available as Qudon (DuPont). [Pg.310]


See other pages where Chromium properties is mentioned: [Pg.226]    [Pg.314]    [Pg.325]    [Pg.361]    [Pg.361]    [Pg.392]    [Pg.115]    [Pg.347]    [Pg.10]    [Pg.238]    [Pg.327]    [Pg.110]    [Pg.124]    [Pg.129]    [Pg.134]    [Pg.136]    [Pg.137]    [Pg.224]    [Pg.403]    [Pg.6]    [Pg.6]    [Pg.7]    [Pg.54]    [Pg.56]    [Pg.458]    [Pg.120]    [Pg.352]    [Pg.554]    [Pg.337]    [Pg.486]    [Pg.370]    [Pg.396]    [Pg.399]   
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See also in sourсe #XX -- [ Pg.980 ]

See also in sourсe #XX -- [ Pg.96 ]




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Chromium atomic properties

Chromium based oxides acid-base properties

Chromium chemical properties

Chromium coatings properties

Chromium complexes magnetic properties

Chromium compounds, general properties

Chromium hexacarbonyl properties

Chromium isotopes and their properties

Chromium nuclear properties

Chromium physical properties

Chromium thermal properties

Chromium thermodynamic propertie

Chromium/silica catalyst support properties

Cobalt/chromium alloys mechanical properties

Magnetic properties chromium

Properties and Applications of Chromium(III) Oxide

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