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Nickel alloys phosphides

The approximately 50 known classes of meteorite, excluding those known to have originated from the Moon or Mars, span a wide range of compositions. Most meteorites are stones. The remaining classes of meteorites, the irons and the stony-irons, are products of melting and differentiation. They consist mainly of metallic iron-nickel alloys, sulfides, carbides, phosphides, and igneous silicates. (See the chapter by M. Lipschutz in this volume). [Pg.136]

Corrosion is further accelerated by the presence of impurities such as oxides, sulphides, carbides, phosphides, and silicates, since these are invariably at a lower potential than the ferrite.3 The influence of alloying elements 4 is particularly interesting. With carbon, for example, cementite or iron carbide, Fe3C, is formed, and as this is electro-negative to ferrite, the latter corrodes at the points of contact. Addition of carbon, therefore, to iron tends to enhance its corrodibility. If a third element is added to the system, its influence upon corrosion is determined largely by the manner in which it distributes itself.5 If it dissolves in the ferrite, reducing its. solution pressure, it reduces the potential difference between the ferrite and cementite, and thus enhances the resistance of the whole to corrosion. Nickel behaves in this manner, the whole of the metal passing into solid solution with the ferrite until the steel contains more than 8 per cent, of nickel. Such steels, therefore, do not readily corrode. [Pg.71]

The bulk metal is oxidized by air or steam only at high temperatures, but Raney nickel (see Section 21.2) is pyrophoric. Nickel reacts with F2 to give a coherent coating of NiF2 which prevents further attack hence the use of nickel and its alloy Monel metal in apparatus for handling F2 or xenon fluorides. With CI2, Bt2 and I2, Ni(II) halides are formed. At elevated temperatures, Ni reacts with P, S and B and a range of different phosphide (see Section 14.6), sulfide and boride (see Section 12.10) phases are known. [Pg.630]


See other pages where Nickel alloys phosphides is mentioned: [Pg.859]    [Pg.393]    [Pg.228]    [Pg.259]    [Pg.859]    [Pg.389]    [Pg.365]   
See also in sourсe #XX -- [ Pg.127 ]




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