Nevertheless, ISO particle counting is an excellent tool for determining the onset of an active wear problem. Using the flow decay method, a sample of oil is passed oil through a calibrated screen that acts like a filter.
It is more likely that they come from surface sliding, welding, ploughing, etc. Most likely, these small spheres occurred with microspalling particles, which are small plate-like particles of less than 30 micron to 50 micron Figure Opt, M X, Filtergram When fatigue wear has deteriorated into a deep-spall, the surface integrity is destroyed.
The run-in period was observed to be 19 months because of the relatively short accumulated working time of the bearing.
The pebble-like particles, which can also be seen as chunky particles, are easily identified by their prominent three-dimensional features.
Micro-Spall Particles Particles that are the result of micro-spalling at an early stage of rolling contact fatigue are called microspall fatigue wear particles. Monitoring and controlling problems that lead to active machine wear are critical to an effective oil analysis strategy.
At this stage, the fatigue cracks have penetrated and propagated deeper into the subsurface, at an angle of approximately 45 degrees to the rolling direction, as illustrated in Figure Formation of Chunky Fatigue Wear Particles2 Thus, the propagation of fatigue cracks has changed direction.
It was feasible to use atomic emissive spectrum and ferrography to monitor the working condition of the converter trunnion bearing. While the operation of each type of instrument is beyond the scope of this article, all instruments generally rely on magnetism to either trap ferrous particles or to detect particles directly using the magnetic Hall effect.
Their aspect ratio ranges between 5-to-1 and 1-to The important takeaway from this method is that it considers both hard and soft contaminants as particles. During the two-year monitoring period, lubricating oils from bearings in the other three converters Nos.
This is because spherical particles are an indication of higher surface temperature. Large spherical ferrous particles greater than 10 micron in rolling element bearings are believed not to be generated in the bearing fatigue cracks.
They have a low aspect ratio of approximately to-1, as shown in Figures 13 and Surface Cracking Particle Indentation Fatigue Wear Particles There are four typical types of wear particles that have been recognized as being representative of rolling contact fatigue: The following is a highly- abbreviated and condensed excerpt from Dr.
Despite these limitations, particle counting has proven to be highly effective at determining the onset of component wear. The microspall particles that are generated this way are relatively small, ranging between 10 micron and 30 micron in their major dimension; however, their major dimension is sometimes as large as 50 micron.
Opt, Surface Pitting of a Bearing Raceway After being repeatedly over-rolled before and after spalling and before dislodging from the bearing surface, laminar particles have several distinct features: Identification Techniques In addition to discussing fatigue wear particle formation and the various types of fatigue wear particles, the fatigue wear particle analysis chapter in Dr.
Opt, M X,Filtergram Laminar particles have high aspect ratios varying between to-1 and to In this apparatus, the test sample is pumped through a precipitator tube, held on an incline across a magnet.
Opt, M X, Ferrogram Small spherical particles of less than 5 micron are frequently found in other lubrication systems - typically in diesel engines associated with normal rubbing wear and sliding wear.
Laminar particles frequently have holes and folds along them, as shown in Figure 9. I appreciate that they do this without even asking me. Opt, Surface Pitting of a Bearing Raceway After being repeatedly over-rolled before and after spalling and before dislodging from the bearing surface, laminar particles have several distinct features: This is where wear analysis comes into play.
Wear particle analysis is a powerful technique for non-intrusive examination of oil-wetted parts of a machine. The particles contained in the lubricant carry detailed and important information about the condition of the machine.
of the In-service Oil Analysis Handbook. diagnoses of oil analysis results.
Machine wear analysis is essentially the analysis of particles in the oil. wear particle analysis techniques can be applied to different types of assets, specific issues are different for industrial. Wear particle analysis, using tools such as ferrous density and ferrographic analysis, can play a valuable role in determining the root cause of active machine wear.
However, unlike many common oil analysis tests that are quantitative in nature, successfully interpreting information on wear. Wear particle analysis is a powerful technique for non-intrusive examination of oil-wetted parts of a machine. The particles contained in the lubricant carry detailed and important information about the condition of the machine.
The most common tests for routine and exception testing are elemental analysis, ferrous density, particle counting, X-ray fluorescence, analytical ferrography and LaserNet FinesTM, the new technique that shows great promise for the future of wear particle analysis. Understanding Particle Counting Methods.
Particle counting is considered by many to be one of the most important test for used oil analysis. Many problems can be quickly and easily identified by monitoring the number and size-distribution of particles in an oil sample.Oil and wear particle anlysis