A close-interval survey (CIS) is a series of structure-to-electrolyte direct current potential measurements performed at regular intervals for assessing the level of cathodic protection (CP) on pipelines and other buried or submerged metallic structures. This article describes the equipment required to perform the CIS. It provides a discussion on the activities that should be performed during the preparation and execution of the CIS. The dynamic stray current identification and compensation by CIS is discussed briefly. The article also explains various factors involved in the validation of CIS data. It concludes with information on CIS data interpretation.

Hardness testing equipment is important as all results from the induction equipment are graded by the hardness testing equipment. This article includes maintenance tips and points to consider regarding hardness test equipment, power supplies, controls, programmable logic controllers, computer systems, water cooling systems, fixtures and machines, air-operated or pneumatic devices, coils, and quench systems. It also presents simple rules that need to be applied while moving the equipment from one location to another.

This article discusses the materials of construction found in pharmaceutical production facilities. The materials discussed are different stainless steels, nickel and nickel-base alloys, titanium, zirconium, impervious graphite, fluoropolymers, and glass-lined steel. The article describes the three primary causes of failure in the manufacture of pharmaceuticals: embedded iron, failures of glass linings, and corrosion under thermal insulation.

Inorganic chemical-setting ceramic linings are one of the most widely used construction materials in designing the protective linings for industrial installations. Monolithic linings can be applied by cast or gunite (shotcreting) methods over steel or concrete as well as brick and mortar masonry. This article provides a discussion on the function of monolithic linings, the advantages of these materials, the types of applications in which these materials can be successfully used, and the limitations of these linings. It describes the application procedures that should be followed to ensure proper installation of a dual-lining system. The industrial applications that illustrate the corrosion resistance and some uses of monolithic linings, as well as other applications in wastewater treatment systems and the chemical industry, are discussed.

This article provides a detailed discussion on the various devices by which cathodic protection (CP) can be applied to pipe-type power transmission cables. These devices include the resistor rectifier, isolator-surge protector, polarization cells, and field rectifiers. The article describes the interference created by stray currents on CP and associated remedial actions.

Vat polymerization (VP) is an additive manufacturing (AM), or three-dimensional (3-D) printing process in which 3-D objects are produced by hardening a liquid polymer into the desired shape. With the introduction of new materials and improvements in material properties, VP offers a good alternative for AM for low-volume production. This overview of the VP process begins with an introduction to two main processes of VP, namely stereolithography apparatus and digital light processing, and then moves on to discuss the characteristics of the feedstocks used as well as their selection criteria. The article then covers safety issues associated with feedstock handling and the manufacturing constraints related to part orientation and design, providing some key tips for VP support structures. This is followed by a discussion on postprocessing/finishing of VP parts. A brief concluding section considers some special topics related to AM process.

There are various coating techniques in practice to prevent the deterioration of steels. This article focuses on dip, barrier, and chemical conversion coatings and describes hot-dip processes for coating carbon steels with zinc, aluminum, lead-tin, and other alloys. It describes continuous electrodeposition for steel strip and babbitting and discusses phosphate and chromate conversion coatings as well. It also addresses painting, discussing types and selection, surface preparation, and application methods. In addition, the article describes rust-preventive compounds and their application. It also provides information on weld-overlay and thermal spray coating, porcelain enameling, and the preparation of enamel frits for steels. The article closes by describing methods and materials for ceramic coating.

This article describes the major issues involved in designing systems with acceptable cold-climate corrosion performance. It discusses the methods used to control corrosion in external and internal environments. The article provides information on the various common causes of corrosion in cold climates. These include improper transportation and storage practices; improper operations and maintenance practices; and construction practices.

This article describes the commonly observed forms of airplane corrosion, namely: general corrosion, exfoliation corrosion, pitting corrosion, microbiologically induced corrosion, galvanic corrosion, filiform corrosion, crevice corrosion, stress-corrosion cracking, and fretting. It discusses the factors influencing airplane corrosion from the manufacturing perspective: design, manufacturing, and service-related factors. The article explains the collection of corrosion data and provides an overview of the implementation and evolution of airline corrosion prevention and control programs and directions being considered in the design for corrosion prevention of airplanes.

This article presents a detailed discussion on the relative performance properties of principal rubber types used in lining applications together with their application, vulcanization and inspection techniques, and material and installation costs.

This article describes the eight chemical cleaning methods, namely, circulation, fill and soak, cascade, foam, vapor-phase organic, steam-injected, on-line chemical, and mechanical cleaning. It presents information on deposit types, solvents used to remove them, and construction material incompatibilities in a table. The article summarizes the uses of chemical cleaning solutions, including hydrochloric acid, phosphoric acid, and sulfamic acid, as well as the additives used to neutralize their impact on corrosion. It discusses the chemical cleaning procedures, including selection of cleaning method and solvent, documentation of cleaning, and corrosion monitoring in chemical cleaning.

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.

Dross, which is the oxide-rich surface that forms on melts due to exposure to air, is a term that is usually applied to nonferrous melts, specifically the lighter alloys such as aluminum or magnesium. This article describes dross formation and ways to reduce it, the economic implications of dross, and in-plant enhancement or recovery of dross. It discusses the influence of the melter type on dross generation and the influence of charge materials and operating practices on melt loss. Fluxing is a word applied in a broad sense to a number of melt-treating methods. The article also discusses the in-furnace treatment with chemical fluxes.

Stray current can be defined as a current in structures that are underground or immersed in an electrolyte that most often accelerate corrosion on a structure where a positive current leaves the structure to enter the earth or an electrolyte. This article provides a description of the principles of stray current and a discussion on the major types of stray current and their properties and prediction methods. It discusses the consequences of stray current and describes the interference tests used for mapping the path of the stray currents. The article also highlights the methods of mitigating the source of stray current.

Inductively coupled plasma atomic emission spectroscopy (ICP-AES) is an analytical technique for elemental determinations in the concentration range of major to trace based on the principles of atomic spectroscopy. This article provides a description of the basic atomic theory, and explains the analytical procedures and various interference effects of ICP, namely, spectral, vaporization-atomization, and ionization. It provides a detailed discussion on the principal components of an analytical ICP system, namely, the sample introduction system; ICP torch and argon gas supplies; radio-frequency generator and associated electronics; spectrometers, such as polychromators and monochromators; detection electronics and interface; and the system computer with appropriate hardware and software. The article also describes the uses of direct-current plasma, and provides examples of the applications of ICP-AES.

The melting process often includes refining and treating the metal. The choice of which type of melting to use depends on a number of factors: type of alloy being melted, the local cost of electric power, and local environmental regulations. This article discusses the principles, furnace types, charging practices of metal melting methods, namely induction melting, cupola melting, arc melting, crucible melting, reaction melting, and vacuum melting, and the refractories and charging practice of reverberatory furnaces. Molten metal treatment of steels and aluminum also is discussed in the article.

Liquid penetrant inspection is a nondestructive method of revealing discontinuities that are open to the surfaces of solid and essentially nonporous materials. This article provides information on physical principles, evolution, description, and processing parameters of liquid penetrant inspection as well as materials used. It discusses some of the more generally used types of equipment used in penetrant inspection and their requirements. The article describes various penetrant methods and their selection criteria and provides information on precleaning and postcleaning of workpieces before and after penetrant inspection. The quality assurance and maintenance of penetrant inspection materials are also discussed. The article concludes with information on specifications and standards applicable to penetrant inspection.

Zinc and zinc alloys require surface engineering prior to coating or use to improve adhesion and corrosion resistance. Die-cast zinc parts, in addition, must be trimmed and finished to remove flash and parting lines. This article covers zinc cleaning procedures as well as coating and finishing processes. It explains how to remove parting lines and presents several mechanical finishing methods, including surface polishing, brushing, controlled shot peening, and buffing. It also provides information on solvent cleaning, emulsion cleaning, aqueous detergent or alkaline cleaning), electrocleaning, acid dipping, and zinc conversion coating treatments.

The major benefit of the implementation of the corrosion-control technologies at Army installations is the extension of the service life of buildings and other structures. This article reviews the exposure of military facilities and equipment to a wide variety of environmental conditions, including soils, waters, or atmospheres of varying corrosivity. It presents the case studies illustrating typical examples of the types of corrosion problems found on military installations. The article describes the various corrosion-control technologies used in military facilities. These include protective coatings and linings, cathodic protection, advanced materials selection and design, water treatment, equipment inspection and monitoring, and below-grade moisture mitigation.