Colmonoy® 88 Material Information

Colmonoy 88

About Colmonoy® 88

Colmonoy® 88 is a hard surfacing alloy patented under the Wall Colmonoy Corporation. This alloy consists of 3% Boron, 0.08% Carbon, 15% Chrome, 3% Iron, 4% Silicon, 17% Tungsten with a balance of Nickel. The combination of complex borides and carbide with the Ni-Cr-B matrix offers excellent hardness (59-64 Rockwell C) and extends the service life of parts exposed to high-temperature abrasion, erosion, corrosion, galling and fretting.

Selection Criteria for Colmonoy® 88 Coatings

Colmonoy® 88 has applications in many different industries and is present in multiple forms including bare rods, powders, ingots, castings, etc. For thermal spray coating applications a powder form is applied for both strength and hardness requirements at elevated temperatures. Colmonoy® 88 also has excellent resistance to abrasion, erosion, corrosion, pitting, galling and fretting.

Properties of Colmonoy® 88 Coatings

  • Excellent hardness due to carbide and boride forming elements (59-64 Rockwell C)
  • Retains reasonable hardness at higher temperatures
  • Good Strength
  • Excellent resistance to wear
  • Good resistance to hot oxidation, sulfidation and erosion
  • Protective oxide layer of chromium oxide on the surface
  • Excellent resistance to pitting corrosion due to high Ni content
  • High bonding strength
  • Dense coating

Potential Coating Benefits

  • Colmonoy® 88 coatings enhance the service life of the product.
  • Coatings are very effective for wear protection.
  • Spray coating technology is efficient and reliable.
  • Good defense against a wide variety of surface attacks and damages.
  • Good combination of metallurgical and mechanical properties.
  • No expected loss of hard phases during coating development.

Disadvantages

  • Due to fusing operation parts have to be able to withstand high temperatures (1950° F) without degrading

Uses and Applications

  • Commonly used in spray and fuse applications.
  • Plastic-extrusion screws, plastic-injection screws and in twin-barrel extruders where wear resistance is required.
  • Triplex and duplex pump plungers, frac-pump plungers and thermowells.
  • Power plant grate bars, hot-cyclone separators, superheater tubes & panels and boiler tubes.
  • Ball valves, pump casings and pump sleeves.
  • Mixing rotors and end plates.
  • Slurry-pipe elbows, coal-discharge chutes and centrifugal scrolls.
  • Wire-drawing capstans.

Spray and Fuse Coatings