This article provides information on the municipal wastewater system components such as piping, pump stations, headworks, clarifiers, aeration structures, digesters, biosolids dewatering equipment, and sludge stabilization. It explains the major corrosion damage mechanisms to which those component parts of the system are exposed. It presents useful guidelines for selecting and using protective coatings in municipal sewerage collection systems and water reclamation facilities in wastewater treatment plants. The article includes annotated flow diagrams of a wastewater collection system, wastewater treatment plants, and spreadsheets listing the most widely used generic coating systems by structure and substrate material. It concludes with a section on quality watchouts when selecting or using protective coatings in municipal wastewater systems.

Corrosion problems and materials selection for emissions control equipment can be difficult because of varied corrosive compounds present and the severe environments encountered. This article discusses the selection of materials for construction of flue gas desulfurization systems. It addresses the problems associated with materials for incinerator off-gas treatment equipment. The off-gases can be classified according to their corrosiveness as: industrial chemical, hospital, municipal solid, and sewage sludge. The article provides information on the selection of materials for the three most common types of dust collection equipment used in bulk solids processing, namely, fabric filters, electrostatic precipitators, and wet scrubbers. It also discusses a wide variety of corrosion problems encountered in chemical and pharmaceutical industries.

This article describes selected U.S. environmental statutes and regulations that are pertinent to material surface finishers. It provides information on the applicability, requirements, and permitting conditions of the Clean Air Act, the Resources Conservation and Recovery Act, the Superfund Amendments and Reauthorization Act, and the Clean Water Act.

This article discusses the methods of pulp production, pulp processing, pulp bleaching, and paper manufacturing. It describes various types of digesters, their construction materials, the corrosion problems encountered, and methods to protect these digesters from corrosion. The article examines the corrosion problems in high-yield mechanical pulping, sulfite process, neutral sulfite semichemical pulping, chemical recovery, tall oil plants, wastewater treatment, and recovery boilers. It explains the stages of chlorine-based and nonchlorine bleaching, process water reuse for elemental chlorine-free and nonchlorine bleaching stages, selection of material for bleaching equipment, developments in oxygen bleaching, and the use of highly corrosion-resistant materials for bleach plant equipment. The article reviews the materials used in the construction of paper machine components and specific corrosion problems that affect them. It discusses the composition and corrosive nature of white water. The article also addresses the corrosion and chemical recovery associated with kraft pulping liquors.

This article provides an overview of the electrochemical nature of corrosion and analyzes corrosion-related failures. It describes corrosion failure analysis and discusses corrective and preventive approaches to mitigate corrosion-related failures of metals. These include: change in the environment; change in the alloy or heat treatment; change in design; use of galvanic protection; use of inhibitors; use of nonmetallic coatings and liners; application of metallic coatings; use of surface treatments, thermal spray, or other surface modifications; corrosion monitoring; and preventive maintenance.

Coating of cast irons is done to improve appearance and resistance to degradation due to corrosion, erosion, and wear. This article describes inorganic coating methods commonly applied to cast irons. The coating methods include plating, hot dip coating, conversion coating, diffusion coating, cladding, porcelain enameling, and thermal spray. Organic coatings have a wide variety of properties, but their primary use is for corrosion resistance combined with a pleasing colored appearance. The article discusses the various types of organic coatings applied to cast irons. Practically any degree of smoothness or roughness and requirement for color and gloss can be filled by organic coatings. The article describes abrasive blast cleaning, abrasive waterjet cleaning and finishing, vibratory finishing, barrel finishing, and shot peening for processing iron castings.

Grinding is an extremely complex process that requires the consideration of a number of elements in order to make a reasonably adroit initial selection of a fluid or fluids for a manufacturing plant. In addition, the disposal of grinding wastes must meet the minimum requirements as recommended by the federal Environmental Protection Agency (EPA) and Resource Conservation and Recovery Act (RCRA) regulations. This article explains the selection considerations of such fluids, as well as the applications and environmental issues related to the grinding processes.

This article focuses on the types, composition, and applications of phosphate coatings and describes the characteristics of phosphate-coated ferrous and nonferrous materials, including steel and aluminum. It addresses five successive process fundamentals: cleaning, rinsing, phosphating, rinsing after phosphating, and chromic acid rinsing. The article describes the techniques for controlling the chemical composition of various phosphating solutions. It discusses the equipment and factors that influence equipment requirements in immersion and spray systems. The article also describes the controlling procedures of coating weight and crystal size. It provides guidelines for choosing phosphate coatings based on application, coating weight requirements, and recommended process parameters. The article concludes with a discussion on safety precautions and the treatment of effluents from phosphating plants.

This article first describes the two methods used in the 1998 U.S. corrosion cost study. In the first method, the cost was determined by summing the costs for corrosion control methods and contract services. In the second, the cost of corrosion was first determined for specific industry sectors and then extrapolated to calculate a national total corrosion cost. The article then reports the results and conclusions of the study. It concludes with information on corrosion prevention strategies.

Corrosion is the deterioration of a material by a reaction of that material with its environment. The realization that corrosion control can be profitable has been acknowledged repeatedly by industry, typically following costly business interruptions. This article describes the electrochemical nature of corrosion and provides the typical analysis of environmental- and corrosion-related failures. It presents common methods of testing of laboratory corrosion and discusses the processes involved in the prevention of environmental- and corrosion-related failures of metals and nonmetals.

This article addresses the forms of corrosion that contribute directly to the failure of metal parts or that render them susceptible to failure by some other mechanism. It describes the mechanisms of corrosive attack for specific forms of corrosion such as galvanic corrosion, uniform corrosion, pitting and crevice corrosion, intergranular corrosion, and velocity-affected corrosion. The article contains a table that lists combinations of alloys and environments subjected to selective leaching and the elements removed by leaching.

This article focuses on the effects of microscopic organisms and the by-products they produce on the electrochemical corrosion of metals. The general characteristics of the microorganisms that facilitate their influence on the electrochemistry of corrosion are discussed. The industries most often reported as being affected by microbiological corrosion are listed, along with the organisms usually implicated in the attack. The article explains that the influence of organisms can be addressed successfully for a corrosion control program by using four types of evidence: metallurgical, microbiological, chemical, and electrochemical. It provides information on the microbiologically influenced corrosion (MIC) of irons and steels, passive alloys (austenitic stainless steels), aluminum alloys, copper alloys, and composites. The article reviews the formation of microbial biofilms and macrofouling films. It also describes the general approaches taken to prevent MIC.

Corrosion is the electrochemical reaction of a material and its environment. This article addresses those forms of corrosion that contribute directly to the failure of metal parts or that render them susceptible to failure by some other mechanism. Various forms of corrosion covered are galvanic corrosion, uniform corrosion, pitting, crevice corrosion, intergranular corrosion, selective leaching, and velocity-affected corrosion. In particular, mechanisms of corrosive attack for specific forms of corrosion, as well as evaluation and factors contributing to these forms, are described. These reviews of corrosion forms and mechanisms are intended to assist the reader in developing an understanding of the underlying principles of corrosion; acquiring such an understanding is the first step in recognizing and analyzing corrosion-related failures and in formulating preventive measures.

This article discusses the environmental influences on protective coating films that can result in deterioration. These environmental factors can be classified into four groups: (1) energy: solar, heat; (2) permeation: moisture, solvent, chemical, and gas; (3) stress: drying and curing-internal stress, and vibration-external stress; and (4) biological influences such as microbiological, mildew, and marine fouling.

This article describes the uses of the liquid carburizing process carried out in low and high temperature cyanide-containing baths, and details the noncyanide liquid carburizing process which can be accomplished in a bath containing a special grade of carbon. It presents a simple formula for estimating total case depth, and illustrates the influence of carburizing temperature, duration of carburizing, quenching temperature, and quenching medium with the aid of typical hardness gradients. The article provides information on controlling of cyaniding time and temperature, bath composition, and case depth, and presents examples that relate dimensional change to several shapes that vary in complexity. It also provides information on the quenchant removal and salt removal processes, lists the applications of liquid carburizing in cyanide baths, and discusses the process and importance of cyanide waste disposal in detail.

This article discusses the identifying characteristics of the forms or mechanisms of corrosion that commonly attack copper metals, as well as the most effective means of combating each. It tabulates the corrosion ratings of wrought copper alloys in various corrosive media. The article describes the corrosion behavior of copper alloys in specific environments. It reviews the corrosion characteristics of copper and copper alloys in various acids, alkalis, salts, organic compounds, and gases. The article provides information on the behavior of copper alloys that is susceptible to stress-corrosion cracking in various industrial and chemical environments. It concludes with information on various corrosion testing methods, including aqueous corrosion testing, dynamic corrosion tests, and stress-corrosion testing.