ASTM D6425 Friction and Wear Properties of Extreme Pressure (EP) Lubricating Oils
ASTM D6425 Standard Test Method for Measuring Friction and Wear Properties of Extreme Pressure (EP) Lubricating Oils Using SRV Test Machine
1. Scope
1.1 This test method covers an extreme pressure (EP) lubricating oil's coefficient of friction and its ability to protect against wear when subjected to high-frequency, linear oscillation motion. The procedure is identical to that described in DIN 51834.
1.2 This test method can also be used to determine the ability of a non-EP lubricating oil to protect against wear and its coefficient of friction under similar test conditions.
1.3 The values stated in SI units are to be regarded as the standard. The values given in the parentheses are for information only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D4175 Terminology Relating to Petroleum, Petroleum Products, and Lubricants
G 40 Terminology Relating to Wear and Erosion
2.2 Other Standards:
DIN 17230 Roller Bearing Steels
DIN 51834, Tribiological Test in the Translatory Oscillation Apparatus (Part 2: Determination of Friction and Wear Data for Lubricating Oils)
3. Terminology
3.1 Definitions:
3.1.1 break-in, n - in tribiology, an initial transition process occurring in newly established wearing contacts, often accompanied by transients in coefficient of friction or wear rate, or both, that are uncharacteristic of the given tribiological system's long term behavior. (Synonym: run-in, wear-in)
3.1.2 coefficient of friction µ or f, n - in tribiology, the dimensionless ratio of the friction force (Ff) between two bodies to the normal force (Fn) pressing these bodies together.
µ = (Ff/Fn)
3.1.3 EP lubricating oil, n - a liquid lubricant containing an extreme pressure (EP) additive
3.1.4 extreme pressure (EP) additive, n - in a lubricant, a substance that minimizes damage to metal surfaces in contact under high stress rubbing conditions.
3.1.5 Hertzian contact area, n - the apparent area of contact between two nonconforming solid bodies pressed against each other, as calculated from Hertz' equations of elastic deformation.
3.1.6 Hertzian contact pressure, n - the magnitude of the pressure at any specified location in a Hertzian contact area, as calculated from Hertz' equations of elastic deformation.
3.1.7 lubricant, n - any substance interposed between two surfaces for the purpose of reducing the friction or wear between them.
3.1.8 wear, n - damage to a solid surface, generally involving progressive loss of material, due to relative motion between that surface and a contacting substance or substances.
3.1.9 C.L.A., n - in measuring surface finish, the arithmetic average of the absolute distances of all profile points from the mean line for a given distance.
3.1.10 Rz, n - in measuring surface finish, the average of all Ry values (peak to valley heights) in the assessment length.
3.1.11 Ry, n - in measuring surface finish, the vertical distance between the top of the highest peak and the bottom of the deepest valley in one sampling length of the roughness profile.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 seizure, n - the stopping of relative motion as the result of interfacial friction.
