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.

This article describes the methodology for performing a failure modes and effects analysis (FMEA). It explains the methodology with the help of a hot water heater and provides a discussion on the role of FMEA in the design process. The article presents the analysis procedures and shows how proper planning, along with functional, interface, and detailed fault analyses, makes FMEA a process that facilitates the design throughout the product development cycle. It also discusses the use of fault equivalence to reduce the amount of labor required by the analysis. The article shows how fault trees are used to unify the analysis of failure modes caused by design errors, manufacturing and maintenance processes, materials, and so on, and to assess the probability of failure mode occurrence. It concludes with information on some of the approaches to automating the FMEA.

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.

Risk and hazard analysis can be effectively used during design reviews to provide valuable feedback to the design to avoid failures. This article discusses the types of risks, namely, real risk, statistical risk, predicted risk, and perceived risk. It describes the principle and technical methods of risk/hazard analysis practiced in the industry to identify possible hazards and the resources necessary to avoid or reduce risks. These methods include the failure mode and effect analysis, fault tree analysis, event tree analysis, risk/benefit analysis, safety analysis, and probabilistic estimates.

This article introduces the concept of condition monitoring (CM) and summarizes various techniques used for CM across the industrial sectors. The techniques include visual inspection, performance monitoring, vibration condition monitoring, vibration condition monitoring, lubricant oil analysis, acoustic emission testing, temperature monitoring, motor current signature analysis, and ultrasound emission. The article describes the evolution of condition-based maintenance in CM. It also describes the basics of integrated vehicle health management, a capability that enables a number of maintenance philosophies. The article concludes with a discussion on various condition monitoring in industrial sectors, including condition-monitoring techniques in nuclear power plants, road condition monitoring, and condition monitoring in wind turbines.

The basic elements of control design are safety, process control, process verification, machine control, productivity, repeatability, and ease of setup. Effective systems of quality control/quality assurance are essential for heat treating practices. This article provides information on process control modes, as well as on process signatures of some items that require control, monitoring, verifying, and logging methods. It provides information on programmable logic controllers that have become efficient in machine control and monitoring. The article describes possible noise issues, National Electric Code clearance requirements, monitoring requirements, and machine accuracy that need to be considered when designing induction equipment.

External corrosion direct assessment (ECDA) is a structured process intended for use by pipeline operators to assess and manage the impact of external corrosion on the integrity of underground pipelines. This article focuses on four steps of ECDA, namely, preassessment, indirect examinations, direct examination, and post assessment. The ECDA tool selection matrix used to determine the tool choices is also presented.

This article reviews the concepts considered important for an understanding of the processes used for preparing cobalt-chromium alloy implants, the microstructures resulting from this processing, and the resulting material properties. The review includes solidification of alloys, diffusionless (martensitic) phase transformation as occurs with face-centered cubic to hexagonal close-packed transformation in cobalt-chromium alloys, and stacking faults and twins and their role in this transformation. It also discusses the strengthening mechanisms that are responsible for the mechanical properties of cast and wrought cobalt alloys. The article contains tables that list the commonly used cobalt alloys and their biomedical applications and chemical compositions. It discusses the mechanical and corrosion properties of cobalt alloys, and provides a description of the microstructure of cobalt alloys.

Melting with induction crucible furnaces (ICFs) is a well-established and reliable technology, and their maintenance must be performed at regularly scheduled intervals to ensure safe operation. This article discusses monitoring of the refractory lining, and presents an overview of the various wear-indication methods, namely, manual checks, ground leakage indication, evaluation of electrical values of the furnace, and temperature measurement. It also presents the working principle, physical restrictions, limitations, and remarks on these methods.

Solidification processing is one of the oldest manufacturing processes, because it is the principal component of metal casting processing. This article discusses the fundamentals of solidification of cast iron. Undercooling is a basic condition required for solidification. The article describes various undercooling methods, including kinetic undercooling, thermal undercooling, constitutional undercooling, and pressure undercooling. For solidification to occur, nuclei must form in the liquid. The article discusses the various types of nucleation: homogeneous nucleation, heterogeneous nucleation, and dynamic nucleation. It reviews the classification of eutectics based on their growth mechanism: cooperative growth and divorced growth. The article concludes with a discussion on the solidification structures of peritectics.

This article provides a discussion on transformers and reactors for induction heating. It presents information on the initial considerations in the selection process and the demands of power supply and load circuits. The article describes the types of transformers and reactors used in induction heating and maintenance operations. It also provides a discussion on load matching covering the following topics: initial considerations in the load-matching process, understanding the load circuit and the power supply circuit, selecting the desired operating point, adjusting the value of components, and testing the setup.

Pure metals normally solidify into polycrystalline masses, but it is relatively easy to produce single crystals by directional solidification from the melt. This article illustrates the dislocations present in a metal crystal, which is often polygonized into sub-boundaries during grain growth after solidification. It provides a description of small-angle and large-angle grain boundaries of polycrystalline metals.

This article describes the various environments affecting corrosion performance, corrosion protection, and corrosion control. These include freshwater environments, marine environments, and underground environments. The article provides information on corrosion in military environments and specialized environments, representing less-well-known environments with more limited applications.

This article provides information on the general structural features and origins of metals. The characteristic structural features of single-phase metals and alloys, such as grain structure and substructure, are discussed. The article also describes the major types of multiphase structures and macrostructure of metals and alloys.

Steel storage tanks are the primary means for storing large volumes of liquids and gaseous products. The stored fluid could be water, but it could also be volatile, corrosive, and flammable fluid requiring special precautions for storage as well. Corrosion is generally worst where the tank is in contact with the soil. This article describes the soil characteristics and addresses cathodic protection (CP) criteria for submerged metallic piping systems. It provides information on the data required for designing a CP system, alone or in conjunction with a protective coating system. These data are collected from predesign site assessments, tank electrical characteristics, and soil-resistivity measurements. The article addresses NACE Standard RP0169, which gives requirements and desired characteristics for coating in conjunction with CP. It also explains the methods of protecting aboveground storage tanks and underground storage tanks.

This article provides information on four different length scales at which surface morphology can be viewed: macro, meso, micro and nanoscale. Elementary thermodynamics demonstrates that a liquid cannot solidify unless some undercooling below the equilibrium (melting) temperature occurs. The article details five types of solidification undercooling, namely, kinetic, thermal, constitutional (solutal), curvature, and pressure undercooling. It explains the types of nucleation which occur in the melt during solidification. The effects of local instabilities at the solid/liquid interface during growth are illustrated. The article also describes the solidification structures of pure metals, solid solutions, eutectics, peritectics, and monotectics.

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.

This article focuses on the analyzing and modeling of stress-strain behavior of polycrystals of pure face-centered cubic (fcc) metals in the range of temperatures and strain rates where diffusion is not important. It presents a phenomenological description of stress-strain behavior and provides information on the physical background, alternative interpretations, and directions of research. The quantitative description of strain hardening of fcc polycrystals is provided. The article also discusses the modeling of stress-strain behavior in body-centered cubic metals, hexagonal metals, stage IV work hardening, and the various classes of single-phase alloys.

This article presents an overview of fatigue crack nucleation from the point of view of the material microstructure and its evolution during cycling. It describes the sites of microcrack nucleation at the free surfaces. The article discusses the relation of dislocation structures and surface relief and reviews the mechanisms of crack nucleation. The damage of material due to crack nucleation, the extent (in terms of the number of cycles) of the nucleation stage, and the factors influencing crack nucleation are discussed.