High temperature corrosion and wear

Weld Metal Overlay a Cost-effective Solution to High-temperature Corrosion and Wear Problems... 

High-temperature corrosion and wear is encountered in various industries such as waste incineration, fossil energy, pulp and paper, petroleum refining, chemical and petrochemical, mining and smelting operations. One of the methods to combat corrosion and wear and its control is to select suitable material, i.e., an alloy, for the plant design and maintenance. The selection of proper material for plant design and fabrication is followed... 

High-Temperature Corrosion and Wear Problems High-temperature corrosion and wear occurs in (i) waste incineration, (ii) fossil energy, (iii) pulp and paper (iv) petroleum refining (v) the chemical and petrochemical industries (vi) mining and smelting operations. 

Marine fuel sulfur can range from 1.5 wt% for DMA to as high as 5.0% for RME and higher-viscosity grades of marine residual fuel. Problems related to sulfur include high SOx emissions and the formation of sulfuric and other acids within the fuel combustion system. At low temperatures, the formation and condensation of acids within the combustion chamber can result in corrosion and wear of metal system components. 

Chromium-containing cobalt alloys have been developed for use requiring wear resistance and high temperature corrosion resistance. The nominal composition of some wear-resistant cobalt alloys is given in Table 4.49. 

This work reports the development of a polymeric/sol-gel route for the deposition of silicon carbide and silicon oxycarbide thin films for applications such as heat-, corrosion-, and wear-resistant coatings, coatings on fibers for controlling the interaction with the matrix in ceramic matrix composites, or films in electronic and optoelectronic devices. This method, in which the pre-ceramic films are converted to a ceramic coating either by a conventional high temperature annealing or by ion irradiation, is alternative to conventional methods such as chemical or physical vapor deposition (CVD, PVD), molecular beam epitaxy, sputtering, plasma spray, or laser ablation, which are not always practical or cost efficient. 

Reliability is often a problem of wear. Wear resistance is the most outstanding feature of cemented carbide. Cemented carbide can also withstand deformation, impact, heavy load, high pressure, corrosion, and high temperature - often the only material that can fulfill these requirements satisfactorily. One restriction is the limited capacity to withstand tensile stresses which has to be considered for the application. Over the years, cemented carbides have also proven their superiority in a great number of other tooling and engineering applications than cutting. 

There are a number of oxide systems as protective coatings, as well as dispersoids, demonstrating superior performance in terms of corrosion and other properties, which will be reviewed later in this chapter. However, in cyclic operating conditions with temperature fluctuations and wear conditions the oxide layers may not be suitable as they can break down due to mismatch of the thermal coefficient of expansion (CTE) with underneath phases, or due to wear, or combination of both, and thereby lead to localized pitting, crevice corrosion, etc., of the underlying substrate. In addition, high temperatures can enhance the diffusion rates. To this end, protective coatings with oxide particle embedded systems are... 

Process industries equipment requiring resistance to high-temperature corrosion, oxidation, and wear... 

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