Search Results for oil degradation

In this article, an in-depth overview of petroleum quenching oils is provided, including oil composition, use, mechanism of the oil quenching processes, oil degradation, toxicology and safety, and quenching bath maintenance.

This article describes the main advantages of using grease as a lubricant rather than oil. It discusses the formulation, lubricating mechanism, degradation, and characterization of grease. The article describes the parameters that determine lifetime of grease, including low-temperature limit, low-temperature performance limit, high-temperature performance limit, and high-temperature limit. The article concludes with information on the practical use of grease as a lubricant reservoir.

This article describes various quenchants, namely, water and inorganic salt solutions, polymers (polyvinyl alcohol, polyalkylene glycol, polyethyl oxazoline, polyvinyl pyrrolidone and sodium polyacrylates), quench oils, and molten salts, which are used for heat treatment of ferrous alloys. It also provides information on the steps for controlling quenching performance for polymer quenchants and oils with an emphasis on measuring quenchant performance, safety measures, and oxidation.

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.

Martempering and austempering processes may eliminate the need for conventional oil quenching and tempering. This article presents the suitability of steels for martempering and austempering. It discusses the compositions of oils suitable for marquenching and modified marquenching and also presents safety precautions recommended for the use of martempering oils. Finally, the article explains the effect of agitation and water in a molten salt bath.

This article presents the fundamentals and nomenclature of polymer quenchants and provides a detailed discussion on the polymers used for quenching formulation. The article describes the effect of polymer structure on the quenching mechanism. It also presents the factors affecting polymer quenchant performance. The article details the use of polymer quenchants for intensive quenching and then focuses on the wire patenting processes and polymer quenchant analysis. The article presents the application of polymer quenchants for induction hardening. Finally, it provides details on cooling curve analysis of polymer quenchants.

This article focuses on the quenching properties of vegetable and animal oils, including toxicity and biodegradability of vegetable/animal oils. The article provides a detailed discussion on the oxidation of vegetable/animal oils. The addition of antioxidants to stabilize soybean and palm oils is discussed, and the article concludes that substantially better performance is required if vegetable oils are to be effective functional equivalents to petroleum oil formulations. This may be done by selecting different vegetable oil compositions with less unsaturation, by applying genetic modification of soybean seed oils, or by chemically modifying and stabilizing the vegetable oil structure.

Paints and protective coatings are the most common means of protecting materials from deterioration. This article focuses on coating degradation that results from the environmental interaction with the coatings. The major environmental influences of the degradation include energy (solar radiation, heat and temperature variation, and nuclear radiation), permeation (moisture, solvent retention, chemical, and oxygen), stress (drying and curing, vibration, and impact and abrasion), and biological influences (microbiological and macrobiological).

This article provides an overview of the interfacial interactions with a lubricant film between a die and a metal, lubricant mechanisms, chemistry, qualification testing, application methods, and property test methods. It focuses on sheet metal-forming operations, although the discussions are relevant to metal-forming operations in general. The article also deals with lubricant selection as influenced by the metal to be formed and particular sheet-metal forming operations. The article also discusses some aspects of microbiology and toxicity in lubricants.

This article focuses on coatings and overlays adopted for use as wear- and corrosion-resistant materials in oil sand processing. It describes the most common application processes for oil sand coatings and overlays, including welding, high-velocity oxyfuel thermal spray, laser cladding, and vacuum brazing. The article provides information on the selection of overlays and materials such as chromium-carbide-base overlays and tungsten carbide metal-matrix composites.

This article provides an overview of common quenching media, the factors involved in the mechanism of quenching, and process variables, namely, surface condition, mass and section size of the workpiece, and flow rate of the quenching liquid. It describes the methods of quenchant characterization using hardening-power and cooling-power tests. The article discusses the fundamentals involved in heat-transfer coefficient and heat flux of quenching processes. This discussion is followed by various actual examples of applications of these methods using simplified equations. Quenchant evaluation, classification, selection, and maintenance are reviewed in detail. The article addresses the various reasons for quench oil variability and complications due to aging and contamination.

This article discusses the environmental influences on protective coating films that can result in deterioration. These environmental factors can be classified into four groups: (1) energy: solar, heat; (2) permeation: moisture, solvent, chemical, and gas; (3) stress: drying and curing-internal stress, and vibration-external stress; and (4) biological influences such as microbiological, mildew, and marine fouling.

This article focuses on lubricants classified as either internal combustion engine or nonengine lubricants, and the lubricant additives. The functional groups of chemically active and inert additives, as well as friction modifiers and other additives, are described in detail. The chemically active additives include dispersants, detergents, antiwear, and extreme-pressure agents, oxidation inhibitors, and rust and corrosion inhibitors. The chemically inert additives include emulsifiers, demulsifiers, pour-point depressants, foam inhibitors, and viscosity improvers. The article also discusses the multifunctional nature of additives and concludes with information on lubricant formulation.

This article presents a general survey of corrosive agents and processes that exist within what are usually considered the protective environments of museums and historic collections. It reviews the corrosion influencing factors, such as humidity, temperature, and light. The article provides a list of pollutants and their sources in museums and collections. It discusses the sources of corrosion, including plastic and wood, sulfur, and carbonyl compounds. The article describes the preservation steps for materials in museum to eliminate the corrosive sources acting on the objects and to avoid other potentially damaging materials.

The function of lubricants is to control friction and wear in a lubricating system containing machine elements such as gears and bearings. This article discusses the basic properties of lubricants to help scientists and engineers understand the principles behind lubricant selection. It reviews the functions of additives, such as friction modifiers, antiwear additives, viscosity modifiers, corrosion inhibitors, oxidation inhibitors, dispersants, and detergents. The article discusses the physical properties of liquid lubricants and the performance characteristics of lubricants. It describes the most common lubricant categories and provides information on the health and safety aspects of using liquid lubricants. The article concludes with a discussion on the lubricant-application method that plays a vital role in how the lubricant functions.