State of the Art and Science Report on Design of Alloys Resistant to High-Temperature Corrosion-Erosion in Coal Conversion Environments

摘要

The state of the art and science of design of alloys resistant to high-temperature erosion-corrosion in coal eonversion environments has been critically reviewed. It is concluded that the state of the art of the application of wear-resistant alloys in a large number of corrosive environments is good, in that a workable solution to such problems can usually be found. Since such fixes involve the modification of the environment by redesign, where possible, to minimize the erosive-wear ©r corrosion factors, and the choice of resistant alloys is based on previous experience or trial and error, the state of the science, however, appears to be poor. This situation arises largely because there is no acceptable correlation of alloy erosion behavior with alloy properties or microstructure, and there are very few available descriptions of the mode of erosion of alloys. Most erosion research has, however, concentrated on severe conditions where erosion is linear with time, and found little difference in erosion rates among conventional-type alloys;under the less severe conditions expected in coal conversion reactors and in many transfer lines, laboratory results suggest the existence of other modes of erosion (or deposition), so that in this area significant scope may exist for alloy design. The form of the interaction of erosion with corrosion is not known, and few studies have been conducted of erosion under corrosive conditions.