Standard Test Method for Condition Monitoring of Phosphate Antiwear Additives in In-Service Petroleum and Hydrocarbon Based Lubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry

Importancia y uso:

5.1 Antiwear additives are commonly used in petroleum and hydrocarbon based lubricants to prevent machinery wear by forming a chemical barrier activated by frictional heat. Antiwear additives that are phosphate based can be measured by FT-IR spectroscopy using the phosphate absorption band. Initially, phosphate antiwear additives will decompose and form a protective film by binding to metal surfaces and through oxidative mechanisms, and so a decrease in the level of phosphate antiwear additive relative to that in the new oil is expected during normal machinery operation. Subsequently, significant depletion of phosphate antiwear additives due to oxidation or hydrolysis can occur when the lubricant is subjected to high temperatures and high levels of moisture. This usually occurs prior to the point where the oxidation of the lubricant begins to accelerate, making trending of phosphate antiwear additives a useful indicator of the lubricant’s remaining in-service life. Monitoring of phosphate antiwear additive depletion is therefore an important parameter in determining overall machinery health and should be considered in conjunction with data from other tests such as atomic emission (AE) and atomic absorption (AA) spectroscopy for wear metal analysis (Test Method D5185), physical property tests (Test Methods D445 and D2896) and other FT-IR oil analysis methods for oxidation (Test Method D7414), sulfate by-products (Test Method D7415), and nitration (Test Method D7624), which also assess elements of the oil’s condition, see Refs (1-6).

Subcomité:

D02.96.03

Referida por:

D7414-22, D7415-22, D7624-22, D7889-21, D7624-22, D7415-22, D7415-22, D7844-22A, D7624-22, D7414-22, D7414-22

Volúmen:

05.04

Número ICS:

75.100 (Lubricants, industrial oils and related products)

Palabras clave:

condition monitoring; differential trend analysis; direct trend analysis; Fourier transform infrared; FT-IR; hydrocarbon based lubricants; in-service petroleum lubricants; infrared; IR; lubricants; oils; phosphate antiwear;