Search Results for corrosive wear

Corrosive wear is defined as surface damage caused by wear in a corrosive environment, involving combined attacks from wear and corrosion. This article begins with a discussion on several typical forms of corrosive wear encountered in industry, followed by a discussion on mechanisms for corrosive wear. Next, the article explains testing methods and characterization of corrosive wear. Various factors that influence corrosive wear are then covered. The article concludes with general guidelines for material selection against corrosive wear.

This article focuses on the corrosion-wear synergism in aqueous slurry and grinding environments. It describes the effects of environmental factors on corrosive wear and provides information on the impact and three-body abrasive-corrosive wear. The article also discusses the various means for combating corrosive wear, namely, materials selection, surface treatments, and handling-environment modifications.

This article describes the methods of wear measurements and a model of corrosive wear in mill atmospheres. It explains the polarization curves of pyrrhotite and high-carbon low-alloy steel in a quartzite slurry with examples. The surfaces of pyrrhotite in contact with mild steel or stainless steel affected by galvanic interaction are discussed. The article contains a table that lists the results of laboratory marked ball wear tests for three types of steel balls in wet grinding of magnetic taconite. It also provides information on the mechanism of electrochemical interaction and relative significance of corrosion and abrasion in wear. Galvanic interactions in multielectrode systems are reviewed. The article presents a case history on the material selection for grinding balls to minimize corrosion loss and the adverse effect on flotation.

This article provides a discussion on the mechanisms of wear and their interactions with gaseous corrosion. The wear mechanisms include abrasive, erosive, fretting, and sliding. The measurement of degradation on combustion walls in coal-fired boilers is discussed. The article concludes with information on the common coating techniques used for wear-corrosion control.

This article focuses on noble and neutral coatings and the requirements necessary to achieve successful industrial applications. These include corrosion and wear control and repair applications in processing and chemical industries, and valve and downhole drilling applications in the petrochemical industry. The article also discusses substrate chemistry and preparation; coating selection process and microstructure; sealing by chemical, post-heat treatments, and laser processing; and thermal spray process alternatives.

Tribocorrosion is the subject dealing with complex, synergistic effects of chemical and mechanical conditions that cause wear. This article begins with a discussion on oxidative wear and corrosive wear, as well as quantitative measurements of corrosion, mechanical wear, and wear-corrosion effects. It illustrates the mechanism of corrosive-abrasive wear and discusses the factors affecting two-body wear. These factors include particle shape, size, density, and hardness; slurry velocity; slurry particle angle of attack; solids concentration in the slurry; hydrodynamic factors; corrosion products and the mass transfer of oxygen. The article describes slurry particle impingement tests and grinding tribocorrosion tests, as well as the factors to be considered for mitigating corrosive wear, such as materials selection, surface treatments, and environment modifications.

This article discusses the composition, properties and applications of bearing steels. It focuses on the typical wear modes that rolling-element bearings experience: contact fatigue wear, abrasive wear, adhesive wear, and corrosive wear. The article provides information on reliability factor and ABMA and ISO environmental factors.

This article provides an overview of the corrosion theory relating to refractories on the basis of acid/base reactions, thermodynamics, and kinetic considerations. The tests to evaluate refractory corrosive wear are reviewed. The article describes the specific refractories used in steel, glass, aluminum, and chemical-resistant applications. Specific material issues that should be considered or evaluated when choosing or using refractory materials are discussed.

Wear is the damage to a solid surface as a result of relative motion between it and another surface or substance. This article discusses the four general ways by which a material can wear, namely, adhesive wear, abrasive wear, fatigue or fatigue-like wear, and corrosive wear. It tabulates the operational classification of wear situations and describes the relationship between wear or wear rate and design parameters. The article reviews the effect of lubrication on wear behavior and the types of lubricants. It illustrates some fundamental criteria that can be applied in the selection of a material for wear applications. The article explains four elements of wear design, such as system analysis, modeling, data gathering, and verification. It concludes with a discussion on the design approach for low-wear computer peripherals.

Engineered components fail predominantly in four major ways: fracture, corrosion, wear, and undesirable deformation (i.e., distortion). Typical fracture mechanisms feature rapid crack growth by ductile or brittle cracking; more progressive (subcritical) forms involve crack growth by fatigue, creep, or environmentally-assisted cracking. Corrosion and wear are another form of progressive material alteration or removal that can lead to failure or obsolescence. This article primarily covers the topic of abrasive wear failures, covering the general classification of wear. It also discusses methods that may apply to any form of wear mechanism, because it is important to identify all mechanisms or combinations of wear mechanisms during failure analysis. The article concludes by presenting several examples of abrasive wear.

This article provides a brief review of the classification and characteristics of cast irons. It describes the processes used to clean iron castings, including mechanical cleaning and finishing and nonmechanical cleaning. The article discusses surface treatments used to extend casting life when resistance to corrosion, wear, and erosion is required. The common methods include electroplating, electroless plating, hardfacing, weld cladding, surface hardening, porcelain enameling, and organic coatings.

Stainless steels are essential for the modern industrial civilization because of their corrosion resistance, especially in the chemical, petrochemical, and food industries. This article discusses the classification of the various types of stainless steels, including martensitic, ferritic, austenitic, duplex (ferritic-austenitic), and precipitation-hardening stainless steels. It presents a checklist of characteristics to be considered in selecting the proper type of stainless steel for a specific application. The article also outlines the need to promote the formation of an effective protective passive layer in stainless steels. It discusses hardness, fatigue and fretting properties, tribological properties, wear resistance, and corrosion-wear process of the S-phase layer. The article describes two thermochemical nitriding techniques of stainless steels: plasma-assisted nitriding techniques and non-plasma assisted nitriding processes. It also describes the difficulties in stainless steel nitriding/carburizing.

Erosion, cavitation, and impingement are mechanically assisted forms of material degradation that often contribute to corrosive wear. This article identifies and describes several tests that are useful for ranking the service potential of candidate materials under such conditions. The tests, designed by ASTM as G32, G73, G75, and G76, define specimen preparation, test conditions, procedures, and data interpretation. The article examines the relative influence of various test parameters on the incubation and intensity of cavitation, including temperature, pressure, flow velocity, and vibration dynamics. It concludes with a discussion on data correlations and the relationship between laboratory results and service expectations.

Rolling is the process of reducing the thickness or changing the cross section of a workpiece by compressive forces applied through a set of rolls. This article emphasizes flat rolling and illustrates basic flat-rolling process used to reduce the thickness of a rectangular cross section. It provides a discussion on hot rolling, cold rolling, and warm rolling, as well as lubrication in rolling. The article reviews the lubrication for iron-base and nickel-base materials, light metals, copper-base alloys, and titanium alloys. It discusses the wear mechanism in rolling: abrasion, adhesion, and fatigue, as well as oxidative and corrosive wear. Surface modification techniques, such as hardening by induction heat treating, weld overlay, thermal spray coating, coating via physical vapor deposition (PVD), and laser surface treatment, are also discussed for improving roll service life.