This chapter discusses material-related problems associated with coal-fired burners. It explains how high temperatures affect heat-absorbing surfaces in furnace combustion areas and in the convection pass of superheaters and reheaters. It describes how low-NOx combustion technology, intended to reduce NOx emissions, accelerates tube wall wastage. It also covers circumferential cracking in furnace waterwalls, thermal fatigue cracking induced by waterlances and water cannons, superheater-reheater corrosion, and erosion in fluidized-bed boilers.

Boilers are engineered systems designed to convert the chemical energy in fuel into heat to generate hot water or steam. This chapter describes boiler applications and types, including firetube boilers, watertube boilers, electric boilers, packaged boilers, fluidized bed combustion boilers, oil- and gas-fired boilers, waste heat boilers, and black liquor recovery boilers. It also describes the operation and working principle of utility or power plant boilers, covering conventional subcritical and advanced supercritical types.

Managing corrosion continues to be a challenge for operators of modern boilers worldwide. This chapter addresses the corrosion-related problems that can occur in boilers burning municipal solid waste (MSW). It describes corrosion mechanisms associated with different environments and alloys. It also discusses corrosion protection methods for furnace waterwalls and superheater tubes in waste-to-energy boilers.

This chapter discusses the effects of corrosion on boiler tube surfaces exposed to water and steam. It describes the process of corrosion, the formation of scale, and the oxides of iron from which it forms. It addresses the primary types of corrosion found in boiler environments, including general corrosion, under-deposit corrosion, microbially induced corrosion, flow-accelerated corrosion, stress-assisted corrosion, erosion-corrosion, cavitation, oxygen pitting, stress-corrosion cracking, and caustic embrittlement. The discussion is supported by several illustrations and relevant case studies.

This chapter discusses the erosion and erosion-corrosion behaviors of metals and alloys. It includes data primarily related to particle-laden gas streams impacting on the metal surface. It also covers properties and applications and provides guidelines for materials selection.

This chapter discusses five forms of mechanically assisted degradation of metals: erosion, fretting, fretting fatigue, cavitation and water drop impingement, and corrosion fatigue. Emphasis is placed on the mechanisms and the factors affecting these forms of degradation.

Sulfur is one of the most common corrosive contaminants in high-temperature industrial environments and its presence can cause a number of problems, including sulfidation. This chapter describes the sulfidation behavior of a wide range of alloys as observed in three types of industrial environments. One environment consists of sulfur vapor, hydrocarbon streams, H2S, and H2-H2S gas; sulfides are the only corrosion products that form under these conditions. Another environment consists of H2, CO, CO2, H2S, and other gases, causing the formation of oxides as well as sulfides in most alloys. The third environment, for which less data exists, contains either SO2 or O2-SO2 mixtures.

This chapter discusses the use of coating methods and materials and their impact on corrosion and wear behaviors. It provides detailed engineering information on a wide range of processes, including organic, ceramic, and hot dip coating, metal plating and cladding, and the use of weld overlays, thermal spraying, and various deposition technologies.

Organic coatings (paints and plastic or rubber linings), metallic coatings, and nonmetallic inorganic coatings (conversion coatings, cements, ceramics, and glasses) are used in applications requiring corrosion protection. These coatings and linings may protect substrates by three basic mechanisms: barrier protection, chemical inhibition, and galvanic (sacrificial) protection. This chapter begins with a section on organic coating and linings, providing a detailed account of the steps involved in the coating process, namely, design and selection, surface preparation, application, and inspection and quality assurance. The next section discusses the methods by which metals, and in some cases their alloys, can be applied to almost all other metals and alloys: electroplating, electroless plating, hot dipping, thermal spraying, cladding, pack cementation, vapor deposition, ion implantation, and laser processing. The last section focuses on nonmetallic inorganic coatings including ceramic coating materials, conversion coatings, and anodized coatings.

This chapter presents the primary considerations and mechanisms for corrosion and how they are involved in the selection of materials for process equipment in petroleum refineries and petrochemical plants. In addition, specific information on mechanical properties, corrosion, sulfide stress cracking, hydrogen-induced cracking, stress-oriented hydrogen-induced cracking, hydrogen embrittlement cracking, stress-corrosion cracking, velocity-accelerated corrosion, erosion-corrosion, and corrosion control is provided.

Alloys containing elements that form volatile or low-melting-point halides are susceptible to high-temperature corrosion attack. This chapter explains how to determine whether such phases are likely to form, and the rate at which they occur, based on thermodynamic data and phase stability diagrams. It provides an extensive amount of high-temperature corrosion data for metals and alloys in gaseous environments containing chlorine and hydrogen chloride; fluorine and hydrogen fluoride; bromine and hydrogen bromide; and iodine and hydrogen iodide.

This chapter provides practical information on surface treatments that work by altering the surface chemistry of metals and alloys. It discusses the use of phosphate and chromate conversion coatings as well as anodizing, steam oxidation, diffusion coatings, and pack cementation. The chapter also covers ion implantation and laser alloying.