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Erosion summary

A good summary of the behavior of steels in high temperature steam is available (45). Calculated scale thickness for 10 years of exposure of ferritic steels in 593°C and 13.8 MPa (2000 psi) superheated steam is about 0.64 mm for 5 Cr—0.5 Mo steels, and 1 mm for 2.25 Cr—1 Mo steels. Steam pressure does not seem to have much influence. The steels form duplex layer scales of a uniform thickness. Scales on austenitic steels in the same test also form two layers but were irregular. Generally, the higher the alloy content, the thinner the oxide scale. Excessively thick oxide scale can exfoHate and be prone to under-the-scale concentration of corrodents and corrosion. ExfoHated scale can cause soHd particle erosion of the downstream equipment and clogging. Thick scale on boiler tubes impairs heat transfer and causes an increase in metal temperature. [Pg.370]

Fig. 1.96 Summary of factors controlling the erosion corrosion of steels in water... Fig. 1.96 Summary of factors controlling the erosion corrosion of steels in water...
In summary, the lag time of drug release may be controlled by the rate at which water penetrates through the coating or shell, the rate of fluid absorption of the polymer layer, the osmotic activity of salts and osmopolymers, the erosion and dissolution rate of the polymer layers and the thickness of the layers or coatings. [Pg.167]

During WW II Albanite and Cordite N were considered among the least erosive propellants According ro Riegel (Ref 3), Albanite is a better flashless propellant than FNH and has low sensitivity to shock Refs l)Summary Technical Reports of Di-... [Pg.119]

Cooling system pipework and components can suffer corrosion and damage (such as cavitation, erosion, and stress corrosion) under a variety of operating conditions and from many causative agents. The various forms that corrosion and damage may take are discussed more fully later in the text however, an instant, if simplistic, corrosion vulnerability summary affecting some common metals and alloys is given in Table 4.2. [Pg.93]

W) up to the high keV range and have been collected in data summaries [5, 10,11], The data shown in Fig. 9.1 are taken from [5] very similar data exist for H and He ion bombardment. All experimental data shown were obtained from the weight loss of polished samples after ion bombardment. In the case of Be, clean surfaces could only be obtained at temperatures above 900 K where Be diffuses through the surface oxide layer [12], while at lower temperatures, oxidation from the residual gas reduced the erosion yield [5]. [Pg.206]

The evaluation of the cavity deposition for the three different regimes of chemical erosion has resulted in the finding, that apart from the emission of volatile hydrocarbons at elevated temperature and physical sputtering of carbon atoms at high energies, predominantly species with sticking coefficients around 0.02 are produced. A summary of results is given in Table 9.1. [Pg.216]

In summary, the main reasons for the refractory failure in gasifiers include high temperature, large and quick temperature changes, erosion by particulate, molten slag attack, slag variation from the feedstock, hot corrosive gases, and alkali vapor attack.48... [Pg.209]

In summary, we can conclude that very small amounts of NazO will cause liquid to form in a fireclay refractory above 1063°C. If the liquid is confined to the surface of the refractory, a glazing effect will prevent serious damage to the refractory. If Na20 concentrations are significant, even a fraction of 1 wt %, a fireclay refractory will be prone to erosion at high temperatures and serious thermal shock at low temperatures. Fireclay refractories would seem to have poor-to-moderate resistance to Na20. [Pg.76]

In summary, the prediction in the late seventies that there would be complete erosion of FVs by IVs by the end of the eighties and the principle of GE of Frankel and Harlan that competition between FVs and FVs favours the former and results in the replacement of the latter, are not valid in the context of sorghum in eastern Ethiopia. In view of these facts, there was not any infra-specific competition between FVs and IVs, rather there is infra-specific complementation between IVs and FVs of sorghum. [Pg.79]


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See also in sourсe #XX -- [ Pg.65 ]




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Erosion, a Capsule Summary

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