Volume 18 - Friction, Lubrication, and Wear Technology Part 24 pdf

destruction of interfacial junctions on a microscopic scale. This is often the basic cause. The period depends on the velocity and on the elastic characteristics of the system. Stick-slip will not occur if the static friction is equal to or less than the dynamic friction. The motion resulting from stick-slip is sometimes referred to as jerky motion (Ref 1). See also spragging . • stiction • A term sometimes used to signify the condition in which the frictional resistance is sufficient to prevent macroscopic sliding (Ref 1). • Stoke (centistoke) • The centimeter-gram-second (cgs) unit of kinematic viscosity (Ref 1). • storage stability • A measure of the ability of a lubricant to undergo prolonged periods of storage without showing any adverse conditions due to oxidation, oil separation, contamination, or any type of deterioration (Ref 5). • Stribeck curve • A graph showing the relationship between coefficient of friction and the dimensionless number ( N/P), where is the dynamic viscosity, N is the speed (revolutions per minute for a journal), and P is the load per unit of projected area. Note: The symbols Z and v (linear velocity) may be substituted for and N, respectively (Ref 1). Stribeck curve: coefficient of frict ion (and type of lubrication) versus dimensionless variable N /P • sulfochlorinated lubricant • A lubricant containing chlorine and sulfur compounds, which react with a rubbing surface at elevated temperatures to form a protective film. Note: There may be a synergistic effect, producing faster reaction than with sulfur or chlorine additives alone (Ref 1). • sulfurized lubricant • A lubricant containing sulfur or a sulfur compound that reacts with a rubbing surface at elevated temperatures to form a protective film. Note: The shear strength of the sulfide film formed on ferrous materials is lower than that of the metal but greater than that of the film formed by reaction with a chlorinated lubricant (Ref 1). • superficial hardness test • See Rockwell superficial hardness test . • surface damage • In tribology, damage to a solid surface resulting from mechanical contact with another substance, surface, or surfaces moving relatively to it and involving the displacement or removal of material. Note: In certain contexts, wear is a form of surface damage in which material is progressively removed. In another context, surface damage involves a deterioration of function of a solid surface even though there is no material loss from that surface. Surface damage may therefore precede wear. • surface distress • In bearings and gears, damage to the contacting surfaces that occurs through intermittent solid contact involving some degree of sliding and/or surface fatigue. Note: Surface distress can occur in numerous forms depending on the conditions under which the bearing or gear was operated and on the nature of the interaction between the contacting surfaces. • surfactant • A chemical substance characterized by a strong tendency to form adsorbed interfacial films when in solution, emulsion, or suspension, thus producing effects such as low surface tension, penetration, boundary lubrication, wetting, and dispersing (Ref 1). See also Rehbinder effect . • sweating • Exudation of bearing material or lubricant due to high temperature (Ref 1). • sweep velocity • The mean of the surface velocities of two bodies at the area of contact. Notes: Occasionally the sum of the velocities is quoted instead of the mean. In rolling, the sweep velocity is also called the rolling velocity (Ref 1). • syneresis (of a grease) • See bleeding . • synthetic oil • Oil produced from chemical synthesis rather than from petroleum. Note: Examples are esters, ethers, silicons, silanes, and halogenated hydrocarbons. • T • tandem seal • A multiple-seal arrangement consisting of two seals mounted one after the other, with the faces of the seal heads oriented in the same direction (Ref 4). • taper section • A section cut obliquely through a surface and prepared metallographically. Note: The angle is often chosen to increase the vertical magnification of surface features by a factor of 5 or 10 (Ref 1). • tapered land bearing • A thrust bearing containing pads of fixed taper (Ref 1). • tapered roller bearing • A rolling-element bearing containing tapered rollers (Ref 1). Tapered roller bearing (cutaway view). Courtesy of D. Huffman, The Timken Company • Taylor vortices • In a journal bearing, vortices formed in a liquid occupying the annular space between two concentric cylinders (Ref 1). • terminal erosion rate • The final steady-state erosion rate that is reached (or appears to be approached asymptotically) after the erosion rate has declined from its maximum value. This occurs in some, but not all, cavitation and liquid impingement tests (Ref 2). • terminal period • In cavitation and liquid impingement erosion, a stage following the deceleration period, during which the erosion rate has leveled off and remains approximately constant (sometimes with superimposed fluctuations) at a value substantially lower than the maximum rate attained earlier (Ref 2). • textile oil • (1) An oil used to lubricate thread or yarn to prevent breakage during spinning and weaving. (2) An oil acceptable for direct contact with fibers during textile production (Ref 1). • thermal taper • See thermal wedge . • thermal wear • Removal of material due to softening, melting, or evaporation during sliding or rolling. Notes: Thermal shock and high-temperature erosion may be included in the general description thermal wear. Wear by diffusion of separate atoms from one body to the other, at high temperatures, is sometimes denoted as thermal wear (Ref 1). • thermal wedge • The increase in pressure due to the expansion of the lubricant, for example, in a parallel thrust bearing. Note: Thermal distortion of the bearing surfaces may also form a wedge shape. This is referred to as thermal taper (Ref 1). • thermoelastic instability • (TEI) In sliding contact, sharp variations in local surface temperatures with the passing of asperities leading to stationary or slowly moving hot spots of significant magnitude (Ref 8). • thickener • A solid material dispersed in a liquid lubricant to produce a grease. Note: Silica, clays, and metallic soaps are widely used as thickeners (Ref 1). • thick-film lubrication • A condition of lubrication in which the film thickness of the lubricant is appreciably greater than that required to cover the surface asperities when subjected to the operating load, so that the effect of the surface asperities is not noticeable (Ref 1). See also thin-film lubrication . • thin-film lubrication • A condition of lubrication in which the film thickness of the lubricant is such that the friction and wear between the surfaces is determined by the properties of the surfaces as well as the viscosity of the lubricant. Notes: Under thin-film conditions, the coefficient of friction is often 10 to 100 times greater than under thick-film conditions and wear is no longer negligible. Boundary lubrication and elastohydrodynamic lubrication are better-defined terms that should be used where possible (Ref 1). • thixotropy • The property of recovering consistency after a decrease as a result of shearing. Note: Thixotropic age hardening is a more prolonged process than the instantaneous increase in apparent viscosity as shear rate decreases, which is found in non-Newtonian fluids (Ref 1). See also rheopectic material . • thrust bearing • A bearing in which the load acts in the direction of the axis of rotation (Ref 1). • tilting-pad bearing • A pad bearing in which the pads are free to take up a position at an angle to the opposing surface according to the hydrodynamic pressure distribution over its surface (Ref 1). • torque • As applied to sealing, a resistance to shaft rotation caused by the frictional drag of the seal. It is normally expressed in foot-pound or inch-pound units (Ref 4). Note: The metric equivalent is N · m (force times distance). • track • The mark made by a seal on the surface with which it mates (Ref 4). • tracking pattern • The path a seal ring makes when in rubbing contact with the mating ring or seal plate (Ref 4). • traction • In rolling contacts, the tangential stress transmitted across the interface. Notes: The traction will in general vary from point to point over the contact area. More generally, traction may denote the force per unit area of contact (Ref 1). • tractive force • The integral of the tangential surface stress over the area of contact (Ref 1). • transfer • In tribology, the process by which material from one sliding surface becomes attached to another surface, possibly as the result of interfacial adhesion. Notes: Transfer is usually associated with adhesion, but the possibility of mechanical interlocking adherence, without adhesive bonding, exists in certain occurrences. Material may also back transfer to the surface from which it came. See also selective transfer . Transfer (schematic) • transmission oil • (1) Oil used for transmission of hydraulic power. (2) Oil used to lubricate automobile transmission systems (Ref 1). • transition diagram • In tribology, a plot of two or more experimental or operating variables that indicates the boundaries between various regimes of wear or surface damage. Notes: The IRG transition diagram is a plot of normal force (ordinate) versus sliding velocity (abscissa), and is used to identify three regions with differing lubrication effectiveness. Various plots have been called transition diagrams, and the context of usage must be established. • tribo- • A prefix indicating a relationship to interacting surfaces in relative motion. • tribochemistry • The part of chemistry dealing with interacting surfaces in relative motion (Ref 1). Note: Tribochemistry broadly encompasses such areas as lubricant chemistry, changes in reactivity of surfaces due to mechanical contact, oxidative wear, and other phenomena. • triboelement • A solid body that is bounded by one or more tribosurfaces and that resides within a tribosystem . Note: This term is often associated with H. Czichos, whose systems approach to tribology identified triboelements. For example, in a pin-on-disk tribosystem, the pin is one triboelement and the disk is another. • tribology • The science and technology of interacting surfaces in relative motion and of the practices related thereto. Notes: This term was introduced in a report by a group set up by the British Department of Education and Science. It was defined in their report "Lubrication (Tribology)" in 1966. The study of wear by erosion or cavitation erosion is included in tribology (Ref 1). (2) Friction, lubrication, and wear science and technology. • tribometer • (1) An instrument or testing rig to measure normal and frictional forces of relatively moving surfaces (Ref 1). (2) Any device constructed for or capable of measuring the friction, lubrication, and wear behavior of materials or components. • tribophysics • That part of physics dealing with interacting surfaces in relative motion (Ref 1). • triboscience • The scientific discipline devoted to the systematic study of interacting surfaces in relative motion. Note: Triboscience includes the scientific aspects of tribochemistry , tribophysics , contact mechanics, and materials and surface sciences as related to tribology . • tribosurface • Any solid surface whose intermittent, repeated, or continuous contact with another surface or surfaces, in relative motion, results in friction, wear, and/or surface damage. Note: The surface of a body subjected to a catastrophic collision would not generally be considered a tribosurface because significant damage to the entire body is involved. • tribosystem • Any functional combination of triboelements, including thermal and chemical surroundings. • tribotechnology • The aspect of tribology that involves engineering application of triboscience and the design, development, analysis, and repair of components for tribological applications. • trimetal bearing • A bearing consisting of three layers. Note: Trimetal bearings are usually made of bronze with a white metal facing and a steel backing (Ref 1). • trunnion bearing • A bearing used as a pivot to swivel or turn an assembly (Ref 1). • turbine oil • An oil used to lubricate bearings in a steam or gas turbine (Ref 1). • U • unctuous • A general term expressing the slippery feel of a lubricant when rubbed with the fingers. Note: It is recommended that this term not be used in English (Ref 1). • uniformly distributed impact test • See distributed impact test . • unlubricated sliding • Sliding without lubricant but not necessarily under completely dry conditions (Ref 1). Note: Unlubricated sliding is often used to mean "not intentionally lubricated," but surface species such as naturally formed surface oxides and other interfacial contaminants may act in a lubricious manner in nominally unlubricated sliding. • V • V-ring seal • A seal consisting of a ring or nested rings that have a V-shaped cross section and that are commonly made from elastomeric material. Note: Spring loading is sometimes used to maintain contact between the seal and its mating surface. It is normally used to seal against axial motion (Ref 4m). • vacuum residue • The residue from vacuum distillation of crude oil (Ref 1). • vapor-phase lubrication • A type of lubrication in which one or more gaseous reactants are supplied to the vicinity of the surface to be lubricated and which subsequently react to form a lubricious deposit on that surface. Note: The surface to be lubricated may exhibit a catalytic effect to permit formation of the lubricating film. • varnish • In lubrication, a deposit resulting from the oxidation and/or polymerization of fuels, lubricating oils, or organic constituents of bearing materials. Note: Harder deposits are described as lacquers, softer deposits are described as gums (Ref 1). • VI improver • An additive, usually a polymer, that reduces the variation of viscosity with temperature, thereby increasing the viscosity index of an oil (Ref 1). • vibratory cavitation • Cavitation caused by the pressure fluctuations within a liquid, induced by the vibration of a solid surface immersed in the liquid (Ref 2). • Vickers (microindentation) hardness number • The numerical value of microindentation hardness obtained using the Vickers (diamond) indenter and calculated as follows: • where HV P (in units of GPa) is the ASTM symbol indicating Vickers microindentation hardness, P is the applied load (in grams), and d 1 and d 2 are the two diagonal lengths of the impression (in m). Notes: To obtain the HV P in kg/mm 2 , as was customary in the past, the factor 18.192 is replaced with 1854.4. The Vickers microindentation hardness test is described in ASTM E 384. A higher-load, macro-Vickers test has also been developed. • viscoelasticity • A combination of viscous and elastic properties that makes the deformation dependent upon both temperature and strain rate (Ref 1). • viscosity • The bulk property of a fluid, semifluid, or semisolid substance that causes it to resist flow. Notes: Viscosity is defined by the equation: • where is the shear stress, v is the velocity, and s is the thickness of an element measured perpendicular to the direction of flow; (dv/ds) is known as the rate of shear. Newtonian viscosity is often called dynamic viscosity, or absolute viscosity. Kinematic viscosity, or static viscosity (v) is the ratio of dynamic viscosity ( ) to density ( ) at a specified temperature and pressure (v = / ). It is recommended that the term static viscosity should not be used (Ref 1m). • viscosity, units of • For absolute viscosity, the centimeter-gram-second (cgs) unit is the poise (dyne · s/cm 2 ), the meter-kilogram-second (mks) unit is the Poiseuille (newton · s/m 2 ), which is equal to the Système International d'Unités (SI) unit (1.0 N · sm -1 = 10 poise), and the English unit is the Reyn (lb · s/in. 2 ), which is not commonly used. For kinematic viscosity, the cgs unit is the Stoke (cm 2 /s), the SI unit is m 2 · s -1 (1.0 m 2 · s -1 = 10 6 centistokes), and the English unit is the Newt (in. 2 /s), which is not commonly used (Ref 1m). • viscosity index (VI) • A commonly used measure of the change in viscosity of a fluid with temperature. Notes: The higher the viscosity index, the smaller the relative change in viscosity with temperature. Two different indices are used: The earlier usage, according to Dean and Davis, applies to oils having a VI from 0 to 100. Extended VI applies to oils having a VI of at least 100. It compares the oil with a reference oil of VI 100 (Ref 1m). • viscous • Possessing viscosity. Note: This term is frequently used to imply high viscosity (Ref 1). • viscous friction • See fluid friction . • W • wear • (1) Damage to a solid surface, generally involving progressive loss of material, that is due to relative motion between that surface and a contacting substance or substances (Ref 2). (2) The progressive loss of substance from the operating surface of a body occurring as a result of relative motion at the surface (Ref 1). Note: The first definition would not necessarily exclude scuffing or galling , in which surface material may be displaced but not removed; however, the second definition requires substance to be removed in order to be considered wear. Sometimes surface damage , which may not involve material removal, is differentiated from wear as defined under the first definition. This Handbook treats wear and surface damage individually. • wear coefficient • In sliding wear, a dimensionless number that usually represents the proportionality factor k in the Archard wear law . Note: The term wear coefficient has been used in other ways than that given in this definition, and when encountered, it is best to verify its meaning from context. • wear constant • A term sometimes used interchangeably with the term wear coefficient ; however, it should not be used because wear rate is often not constant under different sliding conditions, and, therefore, the term is misleading. • wear debris • Particles that become detached in a wear process (Ref 1m). • wear factor • A term that has no unique meaning. When encountered, the meaning of this term must be taken from its immediate context. Sometimes, the term is used to refer to the sliding wear rate in terms of mm 3 N · m. See also specific wear rate . • wear rate • There is no single, standard way to express wear rate. The units used depend on the type of wear and the nature of the tribosystem in which wear occurs. Wear rate can be expressed, for example, as (1) volume of material removed per unit time, per unit sliding distance, per revolution of a component or per oscillation of a body (that is, in sliding wear), (2) volume loss per unit normal force per unit sliding distance (mm 3 /N m, which is sometimes called the wear factor ), (3) mass loss per unit time, (4) change in a certain dimension per unit time, and (5) relative change in dimension or volume with respect to the same changes in another (reference) substance. The manner of expressing wear rate is sometimes prescribed in specific standard test methods. In other cases, standards are established for given sectors of technology (for example, mechanical face seal technology). See the sections on specific wear types in this Handbook for more information. • wear rate (of seals) • The amount of seal-surface wear, stated in terms of mils worn in some designated time period. Note: One commonly used unit is mils per hundred hours (Ref 4m). • wear resistance • The resistance of a body to removal of material by wear processes, expressed as the reciprocal of wear rate. Notes: Wear resistance is a function of the conditions under which the wear process takes place. These conditions should always be carefully specified. Relative wear resistance is sometimes quoted, using arbitrary standards (Ref 1m). • wear scar • The portion of a solid surface that exhibits evidence that material has been removed from it due to the influence of one or more wear processes. • wear transition • Any change in the wear rate or in the dominant wear process occurring at a solid surface. Note: Wear transitions can be produced by an external change in the applied conditions (for example, load, velocity, temperature, or gaseous environment) or by time-dependent changes (aging) of the materials and restraining fixtures in the tribosystem. • wedge effect • The establishment of a pressure wedge in a lubricant (Ref 1). See also wedge formation (2). • wedge formation • (1) In sliding metals, the formation of a wedge or wedges of plastically sheared metal in local regions of interaction between sliding surfaces. Note: This type of wedge is also known as a prow. It is similar to a built-up edge (Ref 1). (2) In hydrodynamic lubrication, the establishment of a pressure gradient in a fluid flowing into a converging channel. Note: This is also known as wedge effect (Ref 1). • weepage • A minute amount of liquid leakage by a seal. Note: It has rather arbitrary limits, but is commonly considered to be a leakage rate of less than one drop of liquid per minute (Ref 4m). • welding • In tribology, adhesion between solid surfaces in direct contact at any temperature (Ref 1). • whirl (oil) • Instability of a rotating shaft associated with instability in the fluid film (Ref 1). • white layer • In tribology, a white-etching layer, typically associated with ferrous alloys, that is visible in metallographic cross sections of bearing surfaces. Note: Some interpretations of white layers involve the presence of amorphous material; however, in other cases, the layer is thought to be finely microcrystalline such that no structure is visible by optical microscopy. See also Beilby layer and highly deformed layer . • white metal (whitemetal) • A light-colored bearing alloy based on tin or lead. Note: Babbitt metal is one of the white metals (Ref 1). • wick lubrication • A system in which the lubricant is delivered to the bearing surface by means of a wick (Ref 1). • wiper • A pad of felt or other material used to supply lubricant or to remove debris (Ref 1). • wiping • In tribology, the smearing or removal of material from one point, often followed by the redeposition of the material at another point, on the surface of two bodies in sliding contact. Note: The smeared metal is usually softened or melted (Ref 1). • work factor • A measure of the stability of a lubricant when subjected to an endurance test. Note: The work factor is expressed as the average value of the ratio of three characteristics (viscosity, carbon residue, and neutralization number) as measured before the test to those same characteristics as measured after the test (Ref 5). • wrapped bush (bearing) • A thin-walled steel bush lined with a bearing alloy, or any other bearing bush made from strip (Ref 1). • wrist pin bearing • The bearing at the crankshaft end of an articulated connecting rod in a "V" engine (Ref 1). References 1. Glossary of Terms and Definitions in the Field of Friction, Wear and Lubrication (Tribology), Research Group on Wear of Engineering Materials, Organisation for Economic Cooperation and Development (OECD), Paris, 1969 2. "Standard Terminology Relating to Erosion and Wear," G 40, Annual Book of ASTM Standards, ASTM 3. M.B. Peterson and W.O. Winer, Ed., Wear Control Handbook, American Society for Mechanical Engineers, 1980 4. A Glossary of Seal Terms, Special Publication SP-1, Soc iety of Tribologists and Lubrication Engineers, 1983 5. E.L. McMurtrey, Ed., High Performance Solid and Liquid Lubricants, Noyes Data Corp., 1987, p 399-402 6. E.A. Avallone and T. Baumeister III, Ed., Marks Standard Handbook for Mechanical Engineers, 9t h ed., 1987, p 8-133 to 8-135 7. E.E. Bisson and W.J. Anderson, "Advanced Bearing Technology," Special Publication SP- 38, National Aeronautics and Space Administration, 1964 8. W.A. Glaeser, Battelle Columbus Laboratories, private communication, 1990 9. K.E. Speer, Diamond-Ceramic Coating of the Future, J. Am. Ceram. Soc., Vol 72 (No. 2), 1989, p 171-191 10. D. Godfrey, Lubr. Eng., Dec 1989, p 750-751 11. Compilation of ASTM Standards, 6th ed., ASTM, 1986 12. Interpreting Service Damage in Rolling Type Bearings, American Society of Lubrication Engineers (now Society of Tribologists and Lubrication Engineers), 1986 13. "Determination of Slurry Abrasivity (Miller Number) and Slurry Abrasion Response (SAR Number)," G 75, Annual Book of ASTM Standards, ASTM 14. A.D. Sarkar, Friction and Wear, Academic Press, London, 1980, p 342-343 Abbreviations, Symbols, and Tradenames Abbreviations and Symbols • a • contact radius for circular contact; semimajor axis of elliptical contact area; area • a 1 • life adjustment factor for reliability; reliability factor for other than 90% reliability; reliability factor to adjust the L 10 life • a 2 • life adjustment factor for special bearing properties; material factor for other than standard bearing steels • a 3 • application or environmental factor, primarily recognizing the lubricant condition within a bearing (can also include alignment, internal load distribution changes, temperature, contaminants [liquid and solid], and fatigue spall criteria); life adjustment factor for operating conditions • A • austenite; ampere; air • A • cross-sectional area; contact area; projected area; solid material • • angstrom • A 1 • cross-sectional area of a scratch • AA • arithmetic roughness; atomic absorption; Aluminum Association • ABS • acrylonitrile butadiene styrene • A c • contact area • ac • alternating current • AC • air cool • Ac 1 • temperature at which austenite begins to form during heating • Ac 3 • temperature at which transformation of ferrite to austenite is completed during heating [...]... SPP • solid particle erosion SPOF • statistical process control SPVF • • • • second-phase particle second-phase (particle) volume fraction SQC • spherically ended pin on flat coupon SRF • • • SRP • strength reduction factor SRM • statistical quality control ST • Standard Reference Materials • self-reinforcing polymer • short transverse (direction) • STA • std • solution-treated and aged • standard • STEM... radial clearance; conductivity • • built-up edge • Ca • CAD/CAM • CAE • • computer-aided design/computer-aided manufacturing corrosion-affected erosion • CANMET • CBED • • Canada Center for Mineral and Energy Technology convergent-beam electron diffraction • CBN • CCT • CCVD • • cubic boron nitride continuous-cooling transformation • • diametrical clearance candela • cd • • • conventional chemical... WRZTA • • wear particle concentration silicon carbide whisker-reinforced alumina • silicon carbide whisker-reinforced, zirconia-toughened alumina • shear power of deformation • Ws • wt% • X • weight percent • water concentration; interfacial constraint parameter • XPS • X • XRD • x-ray photoelectron spectroscopy • load sharing factor • x-ray diffraction • XRF • XTEM • • x-ray fluorescence cross-sectional... melted-vacuum arc remelted • volume • vol • vol% • vr1 • • vr2 • vR volume percent • rolling velocity of pinion • rolling velocity of gear • Rayleigh velocity • VTP • VTR • w • vertical turbine pump • • watt • load; bearing load-carrying parameter; weight of body; abrasive wear resistance; wear volume W • width; mass losses • • video tape recorder W • W12 • WDS • Wf • work of adhesion • • wavelength-dispersive... EDXA • • • • energy-dispersive spectroscopy energy-dispersive x-ray analysis EEC • energy-dispersive spectrometer EELS • • • EHL • Ei electron energy loss spectroscopy EHD • erosion-enhanced corrosion • elastohydrodynamic • elastohydrodynamic lubrication • kinetic energy of an incident ion • flexural rigidity • EI • ELI • extra-low interstitial • ELNES • emf • EP • energy-loss near-edge structure •... ppmm • parts per billion atomic ppm • parts per billion PPS • • parts per million parts per million by mass • polyphenylene sulfide • parts per trillion • ppt • PSD • psi • power spectral density • pounds per square inch • psia • psig • • • gage pressure (pressure relative to ambient pressure) in pounds per square inch PSII • pounds per square inch absolute PSZ • • plasma-source ion implantation partially... coating hardness; composite hardness HB • heat-affected zone • hcp • Hcomp • Hdef • • • • HDPE hexagonal close-packed effective hardness number hardness of highly deformed structure • high-density polyethylene • depth of wear with elastic springback • he • HERF • Hf • high-energy-rate forming • hardness of film • HIP • HK • HLB • • • • Knoop hardness hydrophile-lipophile balance hmin • hot isostatic pressing... (microhardness) • Rockwell microficial (microhardness) • substrate hardness • scratch hardness • Hs • HS • HSLA • • HSS • H/t • high-strength low-alloy HTX • high-speed steel(s) • rate of dry wear • high-temperature crystalline (polymer) • HV • HVOF • • • high-velocity oxyfuel (thermal-spray coating) HVP • Vickers hardness Hz • Vickers hardness at applied force of P • hertz • i • I • Ibs • number of rows of... stress-corrosion cracking • International Organization for Standardization • transmitted electron current joule • ion current density • Jominy equivalent • Boltzmann constant • thermal conductivity; Boltzmann constant; wear factor; wear coefficient • Kelvin • wear coefficient; specific wear rate J • • • • ion scattering spectroscopy J • Jeq • k • k • K • K • kg • kilogram • kilogram force • plane-strain... American Iron and Steel Institute ALB • American Gear Manufacturers Association alcop • • • AMS • AN aluminum-copper bronze Ams • load-bearing area (that is, vertical projection of the contact area) • Amsler circumferential, rotating disk-on-disk machine • Aerospace Material Specification; acoustic material signature • nominal area of contact • annealed • AN • ANSI • Ap • American National Standards Institute . Marks Standard Handbook for Mechanical Engineers, 9t h ed., 1987, p 8-1 33 to 8-1 35 7. E.E. Bisson and W.J. Anderson, "Advanced Bearing Technology, " Special Publication SP- 38, National. sliding wear rate in terms of mm 3 N · m. See also specific wear rate . • wear rate • There is no single, standard way to express wear rate. The units used depend on the type of wear and the. Paris, 1969 2. "Standard Terminology Relating to Erosion and Wear, " G 40, Annual Book of ASTM Standards, ASTM 3. M.B. Peterson and W.O. Winer, Ed., Wear Control Handbook, American Society