Search Results for protection maintenance

This article provides a discussion on the design, in-process, storage, and in-field problems and their considerations associated with armament corrosion with examples. Design considerations include geometry, material selection, assembly, pretreatment, coatings, and working and storage environments. In-process corrosion concerns include processing locations, in-process storage of parts, time between processing steps, and quality control of each processing step. The article also discusses the analysis of the in-field corrosion of the finished product, including physical environments, repair of corrosion-protective coatings, general corrosion-protection maintenance, and appropriate fixes and procedures that can be implemented by soldiers in-field to stop continued corrosion of armament equipment.

This article focuses on technologies in the protective coatings field, namely, polysiloxane hybrids and related materials. Industrial maintenance topcoats, including silicone alkyds, silicone epoxies, and polysiloxanes are reviewed. The article discusses two major application areas of protective coatings, namely, architectural coatings and automotive clear coats.

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.

Acrylic coatings are one of the major generic classes of organic coatings and are prevalent in both architectural and industrial applications. This article provides information on the chemistry of acrylic polymers, the methods used in their manufacture, the relationship between structure and properties when they are formulated into coatings, and how they are being used in coatings. The main discussion points are the differences between solventborne and waterborne technologies and some of the challenges in formulating and applying waterborne acrylic coatings. The article describes the mechanism of film formation of acrylic latex polymers and its effect on final coating properties. It discusses the types of waterborne acrylic latex coatings based on chemical properties and based on applications such as primers, intermediate coats, topcoats, stains, and direct-to-substrate finishes. The article concludes with a description of the advances in the development of waterborne acrylic coatings for maintenance and protective applications.

Maintainability is a function of the durability, damage tolerance, and repairability of a structure. This article discusses the configurations of composite structures, such as sandwich, stiffened-skin, and monolithic structures, used in commercial aircraft composites. It describes the considerations for maintainability of the composite structures during the conceptual design phase. Sources of the defects and damage, such as manufacturing defects and in-service defects, are reviewed. The article describes the nondestructive inspection methods that are used in the repair of composite structures to locate damage, characterize the extent of damage, and ensure post-repair quality. It lists suggestions that can be used as design guidelines for adhesive bonding, general composite structure, sandwich structure, material selection, and lightning-strike protection. The article also provides the basic considerations for personnel, facilities, and equipment during maintenance.

The necessary precursor to a proper and durable finish is the preparation of the active aluminum surface to receive the desired protective finish that will allow it to have a long and attractive service life. This article helps those who work with aluminum in the many varieties of applications of such products. It describes the two main categories of cleaning that can be used with most any metal, namely, mechanical cleaning and chemical cleaning. The article provides a discussion on the laboratory evaluation of cleaners, field testing of cleaners, and cleaner types and procedures. It also describes the special cleaning procedures for aluminum alloys, such as steam cleaning and rotary wire-brush cleaning. The article reviews the use of temporary coatings and the use of maintenance coatings on aluminum. It provides information on the handling and storage procedures of aluminum alloys and the cleaning of specific applications of aluminum.

This article reviews the performance of power electronics components, namely, power rectifiers, insulated-gate bipolar transistors, metal-oxide semiconductor field-effect transistors, diodes, and silicon-controlled rectifiers. It provides information on induction heating power supplies with multiple heat stations, such as switching units and multiple (zone) outputs. The article describes power supply operational control and power supply protection circuits. It details duty cycle, power factor, and harmonics of power supplies. The article also describes system parameters, software analysis-calculations, human analysis-decisions, multiple system arrangements, and zone control systems for power supply selection. It provides information on the maintenance of induction power supplies, detailing the safety precautions to be taken and the need for routine inspection and servicing.

Weathering steels contain deliberate additions of alloying elements intended to increase the atmospheric corrosion resistance of steel. This article provides an overview of atmospheric corrosion testing. It describes the estimation of the atmospheric corrosion behavior of weathering steels by two methods such as short-term exposure tests and calculation of a corrosion index based on the steel composition. The article highlights some generalities about corrosion mechanisms. Based on the mechanism of atmospheric corrosion resistance of weathering steel, working rules for creating the protective oxide film have evolved. The article also provides case histories that illustrate both the violations of these rules and suggestions on how to avoid certain maintenance problems that may be encountered with weathering steels.

This article presents a discussion on the U.S army's position on corrosion control for wheeled tactical vehicles. It addresses the army requirement for corrosion control. The U.S. Army Tank-automotive and Armaments Command (TACOM) defines the corrosion prevention and control requirements in the procurement document. The article summarizes requirements from a procurement document. As required by the procurement contract, corrosion-control technologies used in a vehicle system need to be evaluated to determine their benefit. The article provides information on testing systems, which help to meet the army's needs. It includes information on supplemental corrosion protection, which improves the corrosion resistance of a material.

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 a basic overview of bridge corrosion, where it occurs on steel and concrete bridge structures, and how to prevent corrosion by using coatings. It describes types of bridge designs, with illustrations, and presents information on how corrosion occurs in different bridge zones and areas, with illustrations. The article concludes with a discussion on the common methods of coating systems applications on bridge structures and key elements in coating condition assessment.

This article reviews corrosion problems in the U.S. Department of Defense (DoD) and discusses management and maintenance aspects of the practices that address the cost and readiness. It describes the plans to institute corrosion prevention and control strategies under DoD directives in engineering design, material selection, and fabrication processes for new acquisitions. The article also suggests a long-term strategy to reduce the cost of corrosion control.

This article suggests procedures to increase the availability and function of patterns and tooling. It discusses the common expected failure mechanisms, such as erosion and fatigue, for dies and patterns. A successful maintenance program requires good record keeping for each tool. The article lists information required for the maintenance tooling record and preventive maintenance (PM) items from the North American Die Casting Association's publication E501. It concludes with information on objectives for proper storage of tools and patterns. The objectives are preventing tool degradation, safe workplace, easy location, proximity, and cataloging and tracking.

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.

Reliability-centered maintenance (RCM) is a systematic methodology for preventing failures. This article begins by discussing the history of RCM and uses Society of Automotive Engineers (SAE) all-industry standard JA1011 as its model to describe the key characteristics of an RCM process. It then expands on questions involved in RCM process, offering definitions when necessary. Next, the article describes the approach of RCM to failure modes and effects analysis (FMEA), the failure management policies available under RCM, and the criteria of RCM for deciding when a specific failure management policy is technically feasible. Then, after discussing the ways that RCM classifies failure effects in terms of consequences, it describes how RCM uses failure consequences to identify the best failure management policy for each failure mode. Next, the building blocks of RCM are put together to create a failure management program. The article ends with a discussion on some practical issues pertaining to RCM that lie outside the scope of SAE JA1011.

Reliability-centered maintenance (RCM) is a systematic methodology for preventing failures. This article discusses the history of RCM and describes the key characteristics of an RCM process, which involves asking seven questions. The first four questions comprise a form of failure modes and effects analysis (FMEA), and therefore, the article explains the approach of RCM to FMEA and the failure management policies available under RCM. It reviews the ways that RCM classifies failure effects in terms of consequences and details how RCM uses failure consequences to identify the best failure management policy for each failure mode. The article concludes with a discussion on some practical issues pertaining to RCM that lie outside the scope of SAE JA1011.

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.

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.

Maintenance coating is an important part of any meaningful asset-preservation strategy in facilities producing pulp and paper and other chemicals. This article discusses maintenance coating for carbon steel structures and process equipment exposed to normal external pulp and paper mill atmospheric conditions. The important requirements and standards for surface preparation are emphasized and common issues encountered in maintenance coating projects are described.

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.