Search Results for vehicle accelerated corrosion testing

Complete vehicle accelerated corrosion testing on the proving ground is a mandatory testing tool among vehicle manufacturers around the globe. This article focuses on creating some awareness of the difficulty in applying reliable corrosion tests for all corrosion-sensitive automotive systems at once. It describes the various factors for a complete vehicle testing, including wear from road grit, dirt, salt load, elevated temperatures, and mechanical effects such as chafing and fretting. The article discusses the four main test blocks, namely, driving sequence on various proving ground tracks, exposure of the vehicle in one or more ways to road deicing salts, static exposure to forced climatic conditions, and additional elements such as operating the mechanical systems of the vehicle, car washes, and so forth. It concludes with information on the major advantages and drawbacks of a full-service-life test.

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 discusses the commonly encountered forms of automotive body corrosion. The corrosion forms include general or uniform corrosion, cosmetic or under-film corrosion, galvanic corrosion, crevice corrosion, poultice or under-deposit corrosion, and pitting corrosion. Corrosion-resistant sheet metals, such as electrogalvanized steel, hot dip galvanized steel, and hot dip galvannealed steel, are reviewed. The article provides information on the paint and sealant systems for corrosion control in automotive body applications.

Advances in vehicle design and technology require engine coolant technology to minimize the degradation of nonmetals and prevent the corrosion of the metals in the cooling system. This article provides a detailed discussion on the functions, operation, materials, and major components of the cooling system. It discusses various forms of corrosion that occur in cooling systems, including uniform corrosion, galvanic corrosion, crevice corrosion, pitting corrosion, intergranular corrosion, erosion corrosion, and cavitation corrosion. The article presents information on engine coolant base components and inhibitors used for corrosion prevention. It reviews the coolant performance tests recommended by ASTM, SAE, and vehicle manufacturers. The article concludes with a description on the difference between light-duty automotive and heavy-duty diesel engine coolants.

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.

Steel automotive exhaust systems suffer from various forms of corrosion. This article illustrates exhaust system components with typical upper metal skin temperatures and alloys of construction. It discusses high-temperature corrosion of automotive exhaust systems, including oxidation, hot salt attack, and thermal fatigue. The article describes the various forms of corrosion which occur at the cold end of an exhaust system. The forms of cold end exhaust corrosion, including condensate pitting corrosion, exterior salt pitting, crevice corrosion, intergranular corrosion, and galvanic corrosion.

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.

Aging is a process where the structural and/or functional integrity of components will be continuously degraded by exposure to the environmental conditions under which they are operated. This article discusses aging mechanisms in various components of military systems such as structural parts, engines, and subsystems. It describes the aging management processes such as full-scale structural testing and practical life-enhancement methods. The article reviews control and prevention systems such as usage and health monitoring systems necessary to provide effective corrosion maintenance on military systems. Failure prediction techniques, namely, the equivalent pre-crack size approach, life-cycle cost modeling and simulation, and holistic life-prediction methodology are also discussed.

This article describes the paint systems generally used to protect steel structures, steel sheet, and bridges from corrosion, and how they deter corrosion. It provides a discussion on the basic design criteria of steel structures for corrosion protection. The article also explains the differences between prepaint and postpaint, and the steps involved in prepaint processing of steel. It presents the selection guideline for paint system evaluation. The advantages of corrosion protection are also discussed.

This article provides an overview of the principle forms of corrosion that can occur on automotive aluminum components and offers general guidelines on how best to avoid these situations. It discusses the most common forms of aluminum corrosion such as stress-induced corrosion, cosmetic corrosion, crevice corrosion, and galvanic corrosion.

This article provides a perspective on United States (U.S.) Department of Defense (DOD) specifications, standards, handbooks, and related documents, as well as their role in the corrosion prevention and control activities in the U.S. military.

Steel sheet is often coated in coil form prior to fabrication to save time, reduce production costs, and streamline operations. This article examines the most common precoating methods and provides a metallurgical understanding of how they impact the manufacturability, performance, and service life of the host material. The article covers metallic coatings, including zinc, aluminum, zinc-aluminum alloys, tin, and terne; pretreatment or phosphate coatings; and preprimed and painted finishes based on organic coatings.

This article describes the physical properties of powder metallurgy (PM) stainless steels. These include thermal diffusivity, conductivity, thermal expansion coefficient, Poisson's ratio, and elastic modulus. The article contains a table that lists the characteristics of various grades of PM stainless steels. It discusses the applications of various PM stainless steels such as rearview mirror brackets, anti-lock brake system sensor rings, and automotive exhaust flanges and sensor bosses.

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 use of zinc in corrosion-protective coatings is due to its higher galvanic activity relative to that of steel. Pure zinc dust provides the best sacrificial protection to steel in a galvanic couple. Zinc-rich coatings can be subcategorized according to the type of binder material used, namely, inorganic and organic zinc-rich coatings. Common inorganic binders such as post-cured water-based alkali metal silicates, self-cured water-based alkali metal silicates, and self-cured solvent-based alkyl silicates, are reviewed. The article also compares inorganic and organic zinc-rich coatings, and discusses the concerns regarding zinc-rich coatings.

This article discusses corrosion fatigue, its effects on the damage tolerance of aircraft, and its predictive modeling. A conceptual framework is presented that incorporates two distinctive cyclic-based life-prediction philosophies and expands them both to include the time domain in order to consider the effects of corrosion. These philosophies include crack initiation used for safe-life design and crack growth used for damage tolerance. The article presents the methodology for computing the effects of real-time age degradation on an aircraft structure for two different corrosion types: crevice and pitting corrosion. It describes the rationale and techniques needed to apply the age-based structural integrity processes to in-service structures in order to realize the benefits throughout the full structural life cycle.

This article addresses the impact of emerging technologies on future lubricant and tribology requirements. The connection between lubricant and tribological requirements is shown by briefly describing basic lubrication and friction processes in major engine components incorporating emerging technologies. The article introduces automotive lubricant development activities and the foundation of future automotive engine-lubricant trends. It discusses how emerging powertrain technology impacts future automotive lubricant and technology requirements, focusing on the effects of engine oils and additives on engine performance to meet powertrain performance requirements. A detailed overview of automotive engine oil performance evaluation methods and specifications, and their impact on the types of advanced lubricants being developed as well as future automotive engine testing requirements, is provided.

This article focuses on the general methods and approaches from the perspective of a reconstruction analyst and includes discussions relevant to materials failure analysts at the incident scene. The elements of accident reconstruction are described. These have conceptual similarity with the principles for failure analysis of material incidents that are less complex than a large-scale accident. The article provides a brief review of some general concepts on the use of modeling which can be a very powerful tool for information pertaining to the reconstruction of an accident where the model can be a physical, mathematical, or logical representation of a physical system or process.

This article provides a historical review of corrosion problems in military electronic equipment. It describes the importance of design for corrosion control of an electronic black box used to contain electrical equipment that provides various functions. The article illustrates corrosion control aspects, such as the position of printed circuit boards (PCBs) and proper location of connectors for insertion of the PCBs. It discusses various materials and alloys considered for connectors, PCB contacts, and circuits. The article concludes with a discussion on the effects of contaminants on the electronic black box.

The sealing of the anodized aluminum is a critical process in achieving the durability and extended functionality of anodizing. This article discusses the different methods for sealing the anodic coatings produced by using sulfuric acid, namely, hot deionized water, hot nickel acetate, midtemperature, cold, and dichromate sealing. It reviews the factors that affect seal quality: immersion time, chemistry concentration, temperature, pH, water quality, coating thickness, and contaminants/dye bleeding. The article describes the various tests that are used for determining the quality of the seal, namely, salt spray, modified dye stain, acid dissolution, impedance, copper accelerated acetic acid salt spray, high-alkaline resistance, SO 2 fog, and clorox tests.