Nickel addition

Tables 1 and 2, respectively, Hst the properties of manganese and its aHotropic forms. The a- and P-forms are brittle. The ductile y-form is unstable and quickly reverses to the a-form unless it is kept at low temperature. This form when quenched shows tensile strength 500 MPa (72,500 psi), yield strength 250 MPa (34,800 psi), elongation 40%, hardness 35 Rockwell C (see Hardness). The y-phase may be stabilized usiag small amounts of copper and nickel. Additional compilations of properties and phase diagrams are given ia References 1 and 2.

Copper-alloy corrosion behavior depends on the alloying elements added. Alloying copper with zinc increases corrosion rates in caustic solutions whereas nickel additions decrease corrosion rates. Silicon bronzes containing between 95% and 98% copper have corrosion rates as low as 2 mil/y (0.051 mm/y) at 140°F (60°C) in 30% caustic solutions. Figure 8.2 shows the corrosion rate in a 50% caustic soda evaporator as a function of nickel content. As is obvious, the corrosion rate falls to even lower values as nickel concentration increases. Caustic solutions attack zinc brasses at rates of 2 to 20 mil/y (0.051 to 0.51 mm/y). 

Nickel additions reduce corrosion due to both caustic solutions and ammonia. Monel is resistant to attack in ammonia-containing waters and vapors. Reactions with ammonia are as follows ... 

The grades with the 410 or 420 numerals are the basic 13% chromium type with varied carbon content. The additions of sulphur or selenium (possibly with phosphorus) to some grades (416 group) is to improve machinability. 431S29 has increased chromium content to improve corrosion resistance, but reference to Fig. 3.11 shows that such addition alone would lead to a mixed martensite-5-ferrite structure with certain disadvantages to mechanical properties. The nickel addition is to limit ferrite content. 

Much of the information available on resistance of nickel-iron alloys to corrosion by mineral acids is summarised by Marsh. In general, corrosion rates decrease sharply as the nickel content is increased from 0 to 30-40%, with little further improvement above this level. The value of the nickel addition is most pronounced in conditions where hydrogen evolution is the major cathodic reaction, i.e. under conditions of low aeration and agitation. Results reported by Hatfield show that the rates of attack of Fe-25Ni alloy in sulphuric and hydrochloric acid solutions, although much lower than those of mild steel, are still appreciable (Tables 3.35 and 3.36). In solutions of nitric acid, nickel-iron alloys show very high rates of corrosion. 

Fig. 3.51 Effect of nickel additions to cast iron in reducing corrosion by caustic alkalis...

The steel will be considered to be an ideal ternary solution, and therefore at all temperatures a, = 0-18, Ani = 0-08 and flpc = 0-74. Owing to the Y-phase stabilisation of iron by the nickel addition it will be assumed that the steel, at equilibrium, is austenitic at all temperatures, and the thermodynamics of dilute solutions of carbon in y iron only are considered. 

Fig. 8.17 Effects of applied potential upon the time to failure ratio in slow strain rate tests of C-Mn steel, with and without a 6% nickel addition, in boiling 8 m NaOH, 1 m NaFICOj + 0.5 m Na2COj at 75°C, and boiling 4.4m MgCl2 (after Parkins elat and...

The nickel addition in chromium oxide decreased the formation of alkenes which was smaller than the one observed in the presence of just chromium oxide. It is to be remarked that the decrease of alkene formation was independent of the quantity of nickel in the catalyst. However, the catalytic activity for the fluorination reaction decreased when the nickel content increased. Thus the addition of nickel in small quantities allowed to increase the selectivity for the fluorination reaction. We could suggest that nickel substitute... 

Morgan and Rouge 1984 Toijussen and Andersen 1979). These data do not refer to populations living aroimd the hazardous waste sites that contain elevated levels of nickel. Additional studies which examine nickel levels in body fluids and tissues from persons living near hazardous waste sites that contain elevated levels of nickel would be useful. 

C-M bond addition, for C-C bond formation, 10, 403-491 iridium additions, 10, 456 nickel additions, 10, 463 niobium additions, 10, 427 osmium additions, 10, 445 palladium additions, 10, 468 rhodium additions, 10, 455 ruthenium additions, 10, 444 Sc and Y additions, 10, 405 tantalum additions, 10, 429 titanium additions, 10, 421 vanadium additions, 10, 426 zirconium additions, 10, 424 Carbon-oxygen bond formation via alkyne hydration, 10, 678 for aryl and alkenyl ethers, 10, 650 via cobalt-mediated propargylic etherification, 10, 665 Cu-mediated, with borons, 9, 219 cycloetherification, 10, 673 etherification, 10, 669, 10, 685 via hydro- and alkylative alkoxylation, 10, 683 via inter- andd intramolecular hydroalkoxylation, 10, 672 via metal vinylidenes, 10, 676 via SnI and S Z processes, 10, 684 via transition metal rc-arene complexes, 10, 685 via transition metal-mediated etherification, overview,... 

Atta-Aly, M.A. (1 999) Effect of nickel addition on the yield and quality of parsley leaves. Scientia Horticulturae 82(1-2), 9-24. 

Copper itself is very soft and malleable and it is alloyed with Zn, Sn, Ni and A1 to improve the mechanical properties and to retain its corrosion resistance. Nickel addition allows handling of increased flow rates in water systems while zinc confers greater resistance to sulfide attack. The generic classification of some copper alloys is given in Table 4.25. 

The combustion tests done using a rocket motor demonstrate a typical T combustion instability. Double-base propellants composed of NC-NG propellants with and without catalyst (1 % nickel powder) are burned. The detailed chemical compositions of both propellants are described in Section 6.4.4 of Chapter 6. The burning rate characteristics are shown in Fig. 6-28. No effect of the nickel addition on burning rate is seen and the pressure exponent is n= 0.70 for both propellants. 

Oxide catalysts such as cobalt oxide and nickel oxide233 are recommended for hydrogenation of primary aromatic amines to saturated primary amipes the formation of secondary and tertiary amines, and of deaminated products, is avoided by use of these catalysts. Secondary and tertiary amines can be hydrogenated with Raney nickel. Addition of concentrated hydrochloric acid during hydrogenation of primary unsaturated amines with platinum metals leads predominantly to primary amines. 

We explored the mechanistic implications of the apparent importance of acidity to ammonia selectivity, beginning with the assumption that ammonia is an intermediate in the reduction of nitric oxide over precious metal catalysts. (Attempts to explain our observations on the alternative assumption that chemisorbed isocyanate is the active intermediate (7) were fruitless since nickel should not change isocyanate s behavior. However, an acidic surface would probably lower isocyanate stability.) Since the total conversion of NO increased with nickel addition, it is likely that some conversion takes place on the nickel, probably by the reaction of NO with hydrogen spilled over from the platinum. Disappearance of this ammonia could occur by ammonia decomposition (Reaction 1) as hy-... 

During the years that followed, new types of accelerators were developed in order to decrease the treatment time and temperature. Around 1930, copper and nickel additions were introduced to speed up the reaction and to permit the use of lower temperatures. The rate of the phosphatation reaction was dramatically increased by the introduction of the activation step with Ti colloids by Jemstedt [6] in 1940. The development of spray application methods greatly improved the speed of phosphatation lines, and the phosphatation time has decreased from hours to minutes, and even reduced down to below 10 s for phosphatation on coil coating lines. 

Gessinge GH, Fischmei HF (1972) Modified model for sintering of tungsten with nickel additions. J Less-Common Metals 27 129-141... 

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