Common physical and chemical properties of lubricants

Common physical and chemical properties

(1) Density and Relative density Density refers to the mass of substances contained in a unit volume at a specified temperature, expressed in g/cm3 or kg/m3. Relative density, also known as specific gravity, refers to the ratio of the density of a substance at a given temperature to the density of pure water at a standard temperature. There are no dimensions, and therefore no units. The Chinese standard test methods are GB/T 1884 and GB/T 2540. The corresponding foreign standard test methods include ASTM D4052 and D941 in the United States, IP 160 in the United Kingdom, DIN 51757 and ISO 3675 in Germany. (2) Colourity Colourity is the result measured when the oil color is closest to the color of a certain standard color palette under specified conditions. Chroma is used to initially identify the depth of oil refinement and the degree of oxidative deterioration during use. The Chinese standard test methods are GB/T 3555 and GB/T 6540. The corresponding foreign standard test methods include ASTM D156 and D1500 in the United States, IP 196 and ISO 2049 in the United Kingdom. (3) Viscosity Viscosity is a measure of internal friction when a liquid flows, and it is also the most basic index for evaluating oil fluidity. The viscosity value decreases with increasing temperature. (4) Kinematic viscosity (Kinematic viscosity) Kinematic viscosity is a measure of internal friction when a liquid flows under gravity. Its value is the ratio of the dynamic viscosity of a liquid to its density at the same temperature, expressed in mm2/s in the international system of units .

The Chinese standard test methods are GB/T 265 and GB 11137. The corresponding foreign standard test methods include ASTM D455 in the United States, IP 71 in the United Kingdom, DIN 51562 and ISO 3105 in Germany. The commonly used conditional viscosity in the United States is Saybolt seconds (SUS), and the Redwood second is the commonly used conditional viscosity in the United Kingdom. (5) Dynamic viscosity (Dynamic viscosity) is a measure of internal friction when a liquid flows under a certain shear stress. Its value is the ratio of the shear stress and the shear rate applied to the flowing liquid, in the International System of Units It is expressed in Pa·s, and it is customarily expressed in cP. 1cP=10-3Pa·s. The dynamic viscosity measured at low temperature can indicate the low temperature startability of the oil. The Chinese standard test method is GB/T 506, and the corresponding foreign standard test methods include ASTM D 2983 in the United States, IP 230 and 267 in the United Kingdom, and DIN 53018 in Germany. (6) Viscosity index (Viscosity index) Viscosity index is an approximate quantitative value that represents the characteristics of oil changes with temperature. The higher the viscosity index, the smaller the change in oil viscosity with temperature. Generally expressed in VI.

The Chinese standard test methods are GB/T 1995 and 2541, and the corresponding foreign standard test methods include American ASTM D2270, British IP 226, German DIN 51564 and ISO 2909. (7) Flash point (Flash point) The opening flash point is the flash point measured by the specified opening ± flash point tester, expressed in °C. When the oil is heated under the specified test conditions, and the mixture formed by the oil vapor and the surrounding air comes into contact with the flame, the minimum temperature when a flash fire occurs. Generally speaking, the higher the flash point, the higher the service temperature of the oil. However, the flash point is not equal to the high temperature service limit. The Chinese standard test method is GB/T 3536, and the corresponding foreign standard test methods include American ASTM D 92, British IP 36, German DIN 51376 and ISO 2592. (8) Pour point and Solidification point (Pour point and Solidification point) Pour point is the lowest temperature at which a sample cooled under specified conditions can flow, expressed in °C. The freezing point is the highest temperature at which the sample is cooled to stop moving under specified conditions, expressed in °C.

The pour point or freezing point is a conditional test value and is not equal to the actual flow limit. However, the lower the pour point or freezing point, the better the low temperature properties of the oil. The Chinese standard test methods are GB/T 3535 (pour point) and GB/T 510 (freezing point). The corresponding foreign test methods include American ASTMD97, British IP15, German DIN 51597 and ISO 3016. (9) Acid number (Acid number) The number of milligrams of potassium hydroxide required to neutralize acidic substances in lg oil is called acid number, expressed in mgKOH/g. The acid value is used to reflect the total amount of organic acids contained in the oil, such as naphthenic acid and oil frac34; organic acid products generated by oxidation. The more serious the oxidation of oil, the greater the increase in acid value. Therefore, it is the main indicator of oil deterioration. The Chinese standard test method is GB/T264. (10) Neutralization value (Neutralization value) Neutralization value is a measure of the acidity and alkalinity of oil products. It is also the habitual general term for the acid value or alkalinity value of oil products. It is the alkali or acid required to neutralize a certain weight of oil products. The value expressed by the equivalent amount. The Chinese standard test method is GB/T 4945, and the corresponding foreign standard test methods include American ASTM D 974, British IP 139, German DIN 51588 (1) and ISO 6618. (11) Total Base Number (TBN) The total base number represents the amount of acid required to neutralize all the alkaline components in the lg oil under specified conditions, expressed by the equivalent mg ​​of potassium hydroxide . The total base number is an index for determining the effective additive components in lubricating oil, which indicates the detergency and neutralization ability of internal combustion engine oil. The Chinese standard test method is SH/T 0251, and the corresponding foreign standard test methods include American ASTM D 2896 and 4739, British IP 276, German DIN 51537 and ISO 3771. (12) Saponification value (Saponification value) The saponification value represents the milligrams of potassium hydroxide consumed to neutralize and saponify lg substances under specified conditions. The Chinese standard test method is GB/T 8021, and the corresponding foreign standard test methods include American ASTM D 94, British IP 136, German DIN 51559 (1) and ISO 6293. (13) Conradson carbon residue Conradson carbon residue is the carbon residue measured by the Conradson carbon residue tester. Under the specified test conditions, the residual carbon residue after burning is called carbon residue due to heat evaporation. The value of residual carbon is related to the depth of oil refining and the degree of deterioration during use. The Chinese standard test method is GB/T 268. The corresponding foreign standard test methods include American ASTM D 189, British IP 13, German DIN 51551 and ISO 6615.(14) Water content Water content refers to the water content in oil products. Water is generally not allowed in the oil. The Chinese standard test method is GB/T 260, and the corresponding foreign standard test methods include American ASTM D95 and 1123, British IP74, German DIN 51582 and ISO 3733. (15) Ash content (Ash) Ash content represents the residue frac34 after the oil is carbonized under the specified conditions; the inorganic matter obtained from calcination, expressed in %. The ash in the oil will increase the carbon deposits in the engine and increase the wear of the parts. The Chinese standard test method is GB/T 508, and the corresponding foreign standard test methods include American ASTM D 1119 and ISO 6245. (16) Sulfated ash content (Sulfated ash content) Sulfated ash content represents the carbonized residue of oil products frac34 under specified conditions; sulfuric acid treatment, converted to sulfate after burning constant weight, expressed in %. This method is suitable for determining the sulfate ash content of additives and lubricants containing additives. The Chinese standard test method is GB/T 2433, and the corresponding foreign standard test methods include American ASTM D 874, British IP 163, German DIN 51575 and ISO 3987. (17) Mechanical impurities (Mechanical impurities) Mechanical impurities are all impurities in the oil that are insoluble in solvents. The Chinese standard test method is GB/T 511. (18) Insolubles (Insolubes) The oil is dissolved in an organic solvent, and the impurities remaining on the filter paper through filtration are the insolubles. The Chinese standard test method is GB/T 8926, which is suitable for the determination of n-pentane and toluene insolubles in used lubricating oil. The corresponding foreign standard test methods include ASTM D893 and D4055 in the United States, DIN 51365E and 51392E in Germany, etc. (19) Foaming characteristics: Foaming characteristics are the foaming tendency and foam stability of oil products measured under specified conditions, which can be used to judge the separation ability of oil and gas after mixing with air. The Chinese standard test method is GB/T 12579, and the corresponding foreign test methods include American ASTM D892, British IP 146, German DIN 51566E and ISO DP 6247. (20) Demulsibility Demulsibility is the ability of the emulsion formed by oil and water to divide into two layers. The Chinese standard test methods are GB/T 8022 and 7305, and the corresponding foreign standard test methods include American ASTM D2711 and 1401, British IP 19, German DIN 51599 and ISO 6614. (21) Anline point (Anline point) The lowest temperature at which an oil product is completely miscible with an equal volume of aniline under specified conditions is called the aniline point, expressed in °C. The lower the aniline point, the higher the aromatic content in the oil. The Chinese standard test method is GB/T 387, and the corresponding foreign standard test methods include American ASTM D 611, British IP 64, German DIN 51787 and ISO 2977. (22) Sulfur content (Sulfur content) Sulfur content is the content of sulfur and its derivatives (hydrogen sulfide, mercaptans, disulfides, etc.) present in the oil, expressed in %. It mainly reflects the refinement depth of oil products and the composition characteristics of the processed crude oil. The Chinese standard test method is GB/T 387, and the corresponding foreign standard test methods include American ASTM D 1552, British IP 243, German DIN 51400 and ISO4260. (23) Corrosion test Corrosion test is a test to test the corrosive effect of oil on metals under specified conditions to qualitatively judge the amount of acidic substances in the oil. The Chinese standard test methods are GB/T 391 and SH/T 0195, and the corresponding foreign standard test methods include ASTM D130 in the United States, IP 154 and ISO2160 in the United Kingdom. (24) Anti-rust (Rust? preventing characteristics) Anti-rust is the ability of oil to prevent the metal in contact with it from rusting. The Chinese standard test method is GB/T 11143, and the corresponding foreign standard test methods include American ASTM D 665, British IP 135, German DIN 51585 and ISO 7120. (25) Distillation range (Distillation range) Distillation range is the temperature range that is obtained by distillation of oil under specified conditions and is characterized by initial boiling point and final boiling point. The Chinese standard test method is GB/T 255, and the corresponding foreign standard test methods include American ASTM D86, British IP 123, German DIN 51567 and ISO 3405. (26) Oxidation stability (Oxidation stability) Oxidation stability is the oil's ability to resist the action of the atmosphere (or oxygen) and maintain its properties without permanent changes. The Chinese standard test method is GB/T 12581, and the corresponding foreign standard test methods include American ASTM D 943, British IP 54, German DIN 51587 and ISO 4263. In addition, there is the rotating oxygen bomb measurement method SH/T 0193, and the corresponding foreign standard test methods include ASTM D2272 in the United States and so on. (27) Evaporation loss (Evaporation loss) Evaporation loss is the weight percentage of oil loss after evaporation under specified conditions. The Chinese standard test method is GB/T 7325, and the corresponding foreign standard test methods include ASTM D 972 and D2887 in the United States, and DIN 51581 in Germany.