Thermal high-temperature alloys

The requirements, development and fabrication of electrical insulator and corrosion protection coatings for high-temperature alloys using thermal CVD coatings have been demonstrated. This chapter focuses on the requirements and applications of electrical... 

Carburization involves the formation of internal carbide precipitates. For reasons discussed in Section 5.4, internal carburization is deleterious to the service life of a high-temperature alloy, particularly if the alloy is subjected to thermal cycling down to room temperature. Carburization is a problem mainly for components exposed to process environments above about 900 °C and containing a high content of CO, CH4, or other hydrocarbons. As an example, severe carburization occurs in the cracking tubes used in ethylene and other olefin plants (Kane and Cayard, 1995). Carburization can also be a problem in the heat-treatment of components associated with carbur-... 

Nickel—Copper. In the soHd state, nickel and copper form a continuous soHd solution. The nickel-rich, nickel—copper alloys are characterized by a good compromise of strength and ductihty and are resistant to corrosion and stress corrosion ia many environments, ia particular water and seawater, nonoxidizing acids, neutral and alkaline salts, and alkaUes. These alloys are weldable and are characterized by elevated and high temperature mechanical properties for certain appHcations. The copper content ia these alloys also easure improved thermal coaductivity for heat exchange. MONEL alloy 400 is a typical nickel-rich, nickel—copper alloy ia which the nickel content is ca 66 wt %. MONEL alloy K-500 is essentially alloy 400 with small additions of aluminum and titanium. Aging of alloy K-500 results in very fine y -precipitates and increased strength (see also Copper alloys). 

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