Why Using the G65 Test Makes Sense
When materials are exposed to an abrasive environment, the media flow rubs against them, often leading to material loss over time. This can be mitigated by carefully choosing the correct material for abrasive areas.
The G65 Test can help with this decision, allowing the user to rank the performance of different materials when exposed to a controlled, abrasive environment.
G65 Test Procedure
Measured quantity refers to mass loss during the test. It is converted to volume loss, allowing materials of different densities to be compared for a specified procedure/environment.
Process and Tips
- A small sample of the material to be tested is used
- The sample is pressed against a rubber wheel using a lever arm
- The lever arm provides a controlled/known force
- Sand falls onto the wheel at the sample
- The sand is forced along the surface of the sample by the wheel, causing abrasion
- The force of the lever arm and length of test can vary
- When performing the test, the environment is tightly controlled, as temperature, humidity, abrasive sand particle geometry, etc. will all have large impacts on test results
How to Use the G65 Test Results
- Materials that have a higher resistance to abrasive environments will have a lower volume loss
- Results cannot be used to predict the wear of a material in conditions other than those in which the test was executed
- Make sure to consider how the actual operating/design environment differs from the test. For example, it may change day to day due to temperature, humidity, media size, flow and velocity, etc.
- In fact, ASTM specifies that the results of the test be used only to compare and rank the performance of various materials in a specific, abrasive environment, and not to predict the exact performance of a material in any general abrasive environment
- Chromium content/properties and heat treatment processes also affect the wear rate of the material
Read: “How to Heat Treat ASTM A532” for tips on heat treating chrome white iron.
High Chrome White Iron (ASTM A532) and the G65 Test
Figure 3: Comparing white iron G65 results with those of other materials
In the figure above, you can clearly see that white iron 27Cr-3.5C has less volume loss than CCO, making it a better choice for use in an environment like the Oil Sands.
- Figure 2 – “Comparison of Some Laboratory Wear Tests and Field Wear in Slurry Pumps”, C.I. Walker, P. Robbie. August 23, 2012
- Figure 3 -“Wear of Hydrotransport Lines in Athabasca Oil Sands”, L.L. Parent, D.Y. L. September 16, 2012