Search Results for corrosion-related failures

High temperature corrosion may occur in numerous environments and is affected by factors such as temperature, alloy or protective coating composition, time, and gas composition. This article explains a number of potential degradation processes, namely, oxidation, carburization and metal dusting, sulfidation, hot corrosion, chloridation, hydrogen interactions, molten metals, molten salts, and aging reactions including sensitization, stress-corrosion cracking, and corrosion fatigue. It concludes with a discussion on various protective coatings, such as aluminide coatings, overlay coatings, thermal barrier coatings, and ceramic coatings.

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.

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.

High-temperature corrosion can occur in numerous environments and is affected by various parameters such as temperature, alloy and protective coating compositions, stress, time, and gas composition. This article discusses the primary mechanisms of high-temperature corrosion, namely oxidation, carburization, metal dusting, nitridation, carbonitridation, sulfidation, and chloridation. Several other potential degradation processes, namely hot corrosion, hydrogen interactions, molten salts, aging, molten sand, erosion-corrosion, and environmental cracking, are discussed under boiler tube failures, molten salts for energy storage, and degradation and failures in gas turbines. The article describes the effects of environment on aero gas turbine engines and provides an overview of aging, diffusion, and interdiffusion phenomena. It also discusses the processes involved in high-temperature coatings that improve performance of superalloy.

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 focuses on the various types of corrosion-related failure mechanisms and their effects on passive electrical components. The types include halide-induced corrosion, organic-acid-induced corrosion, electrochemical metal migration, silver tarnish, fretting, and metal whiskers. The passive electrical components include resistors, capacitors, wound components, sensors, transducers, relays, switches, connectors, printed circuit boards, and hardware.

This article describes the corrosion mechanisms, challenges, and control methods in service water distribution systems. It provides a discussion on typical designs and water qualities for distribution systems used in fossil-fueled and nuclear power plants. The article also explains the techniques for controlling corrosion in service water systems.

This article describes the two critical goals in a failure investigation: damage mechanisms and damage modes. It explains the determination of primary and secondary damage mechanisms and discusses the methodology used to classify the damage mechanisms.

The recreation industry covers a huge number of sports, games, and activities that take place in environments as diverse as the activities themselves. This article addresses the corrosive attack on recreational equipment, such as recreational boats, firearms, bicycles, playground equipment, and climbing gear. It discusses the procedures for base materials selection, surface treatments and coatings, and good practice of maintenance to mitigate corrosion while addressing other functional issues for a given piece of equipment.

This article provides information on various forms of corrosion that occur in electronic packaging. Portable consumer electronic hardware which is subjected to humidity exposures is prone to condensed moisture and liquid damage. The article discusses two other corrosion-related phenomena that are found only in electronics, namely, electrochemical migration (ECM) and conductive anodic filament formation (CAF). It describes the corrosion that takes place in metals such as copper, tin, and tin-lead alloys, which are commonly used in electronic packaging. The article also discusses the corrosion of the components used in electronic assemblies.

This article focuses on failure analyses of aircraft components from a metallurgical and materials engineering standpoint, which considers the interdependence of processing, structure, properties, and performance of materials. It discusses methodologies for conducting aircraft investigations and inspections and emphasizes cases where metallurgical or materials contributions were causal to an accident event. The article highlights how the failure of a component or system can affect the associated systems and the overall aircraft. The case studies in this article provide examples of aircraft component and system-level failures that resulted from various factors, including operational stresses, environmental effects, improper maintenance/inspection/repair, construction and installation issues, manufacturing issues, and inadequate design.

This article describes mechanical/electrochemical phenomena related to in vivo degradation of metals used for biomedical applications. It discusses the properties and failure of these materials as they relate to stress-corrosion cracking (SCC) and corrosion fatigue (CF). The article presents the factors related to the use of surgical implants and their deterioration in the body environment, including biomedical aspects, chemical environment, and electrochemical fundamentals needed for characterizing CF and SCC. It provides a discussion on the use of metallic biomaterials in surgical implant applications, such as orthopedic, cardiovascular surgery, and dentistry. It addresses key issues related to the simulation of an in vivo environment, service conditions, and data interpretation. These include the frequency of dynamic loading, electrolyte chemistry, applicable loading modes, cracking mode superposition, and surface area effects. The article explains the fundamentals of CF and SCC, and presents the test findings from laboratory, in vivo, and retrieval studies.

This article briefly introduces the concepts of failure analysis, including root-cause analysis (RCA), and the role of failure analysis as a general engineering tool for enhancing product quality and failure prevention. It initially provides definitions of failure on several different levels, followed by a discussion on the role of failure analysis and the appreciation of quality assurance and user expectations. Systematic analysis of equipment failures reveals physical root causes that fall into one of four fundamental categories: design, manufacturing/installation, service, and material, which are discussed in the following sections along with examples. The tools available for failure analysis are then covered. Further, the article describes the categories of mode of failure: distortion or undesired deformation, fracture, corrosion, and wear. It provides information on the processes involved in RCA and the charting methods that may be useful in RCA and ends with a description of various factors associated with failure prevention.

A corrosionist refers to a corrosion engineer, a corrosion technician, a corrosion scientist, a chemist, a physicist, an electrical engineer, a mechanical engineer, a coatings or plastics salesperson, a corrosion consultant, or a plant operator. This article presents an overview of statistical inference and addresses the commonly used statistical tools and tests. It describes the science and engineering of materials, including metals, polymers, and ceramics. The article explores the principles of various surface-sensitive techniques and the usefulness and limitations of these techniques. The techniques are divided into those that provide insight into surface topography and surface structure, and those that provide understanding of chemical nature and identity. The article presents a list of web sites and print media addressing corrosion and related topics in five different areas: societies and associations; corrosion standards, specifications, and recommended practices; sources of corrosion information; corrosion databases and data compilations; and other web resources.

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 briefly introduces the concepts of failure analysis and root cause analysis (RCA), and the role of failure analysis as a general engineering tool for enhancing product quality and failure prevention. It reviews four fundamental categories of physical root causes, namely, design deficiencies, material defects, manufacturing/installation defects, and service life anomalies, with examples. The article describes several common charting methods that may be useful in performing an RCA. It also discusses other failure analysis tools, including review of all sources of input and information, people interviews, laboratory investigations, stress analysis, and fracture mechanics analysis. The article concludes with information on the categories of failure and failure prevention.

The types of metal components used in lifting equipment include gears, shafts, drums and sheaves, brakes, brake wheels, couplings, bearings, wheels, electrical switchgear, chains, wire rope, and hooks. This article primarily deals with many of these metal components of lifting equipment in three categories: cranes and bridges, attachments used for direct lifting, and built-in members of lifting equipment. It first reviews the mechanisms, origins, and investigation of failures. Then the article describes the materials used for lifting equipment, followed by a section explaining the failure analysis of wire ropes and the failure of wire ropes due to corrosion, a common cause of wire-rope failure. Further, it reviews the characteristics of shock loading, abrasive wear, and stress-corrosion cracking of a wire rope. Then, the article provides information on the failure analysis of chains, hooks, shafts, and cranes and related members.