DIFFUSION COATINGS FOR CORROSION RESISTANT COMPONENTS IN COAL GASIFICATION SYSTEMS

Krishnan, Gopala N. ; Malhotra, Ripudaman ; Sanjurjo, Angel

SRI International (United States)

关键词: Coal Gasification;    Corrosion;    Alloys;    Operating Cost;    Sulfidation;   

DOI  :  10.2172/828177
RP-ID  :  NONE
RP-ID  :  FC26-03NT41616
RP-ID  :  828177

美国|英语

来源: UNT Digital Library

【 摘 要 】

Heat-exchangers, filters, turbines, and other components in integrated coal gasification combined cycle system must withstand demanding conditions of high temperatures and pressure differentials. Under the highly sulfiding conditions of the high temperature coal gas, the performance of components degrade significantly with time unless expensive high alloy materials are used. Deposition of a suitable coating on a low cost alloy may improve is resistance to such sulfidation attack and decrease capital and operating costs. A review of the literature indicates that the corrosion reaction is the competition between oxidation and sulfidation reactions. The Fe- and Ni-based high-temperature alloys are susceptible to sulfidation attack unless they are fortified with high levels of Cr, Al, and Si. To impart corrosion resistance, these elements need not be in the bulk of the alloy and need only be present at the surface layers.