Surfaces subjected to low stress abrasion show that material has been removed by hard, sharp particles or other hard, sharp surfaces plowing material out in the furrows. Grinding with a surface grinder can be a controlled form of low stress abrasion. The low stress qualifier means that the abradant is imposed on the surface with relatively low normal forces. The operating forces must be low enough to prevent crushing the abradant. Low stress abrasion rates are directly proportional to the sliding distance and the load on the particles or protuberances. The wear rate is significantly reduced by hard micro constituents within the surface microstructure (embedded carbides for example).
The ASTM G65 test simulates sliding abrasion conditions under moderate pressure, using dry sand metered between a rubber wheel and a block coupon of the material being evaluated. The test allows comparison of wear-resistant materials by their volume loss in cubic millimeters, with materials of higher wear resistance showing lower volume loss.
Test Conditions
Tested for 6000 revolutions at a load of 30 lb. (13.6 kg) using a 9 inch (229 mm) diameter rubber wheel and dry sand.
Low-Stress Abrasion
Abrasive wear occurs when hard particles are compressed with normal pressure against the surface of a metal, causing material removal.
Coating or Alloy | Chemical Composition | Application Process | HRC Rc | Volume Loss mm3 |
---|---|---|---|---|
C9000 | Formulation – Nano Tungsten Carbide, Cobalt | HVOF | 68-71 | 4.5 |
C1000 | Formulation – Tungsten Carbide, Cobalt | HVOF | 68-71 | 5.5 |
C1000Ni | Formulation – Tungsten Carbide, Cobalt, Nickel Matrix | HVOF | 68-71 | 5.2 |
C1000Cr | Formulation – Tungsten Carbide, Cobalt, Chrome | HVOF | 69-70 | 6.6 |
C1000-17 | Formulation – Tungsten Carbide, Cobalt Matrix | HVOF | 66-68 | 7 |
C5000 (CPR) | Formulation – Carbides within a Nickel-Chrome Matrix | HVOF | 58-62 | 7.7 |
C1000SF | Formulation – Tungsten Carbide, Nickel Chrome Boron | HVOF | 62-65 | 10.3 |
C6000 | Formulation – Carbon, Chromium, Tungsten, Nickel | HVOF | 58-62 | 13.2 |
Carboride 35Wc | 35% Tungsten Carbide + Nickel Chrome Boron | PTA/HVOF | 60 | 15.3 |
Colmonoy 83 | Ni/Cr/Boron/WC | Weld overlay | 48 | 16.5 |
CPM-9V (HIP) | Iron-Chrome-Vanadium-Moly | Powder Metallurgy | 54-56 | 16.8 |
C4000 | Formulation – Chrome Carbide, Chromium, Nickel | HVOF | 55-60 | 19.1 |
HCP | Hard Chrome Plating | Plating | 68-72 | 28.6 |
Colmonoy 56 | Ni/Cr/Boron | Weld overlay | 49 | 33.4 |
D2 Steel (1.2379) | Chrome Carbide Tool Steel | Wrought steel | 58-60 | 36.1 |
Stellite 6 | Co/Cr/W | Weld overlay | 40 | 55 |
Nitralloy (1.8550)* | Nitrided Nitralloy Steel | Wrought steel | 70 | 68 |