Colmonoy

In recent years, the spraying process has been adapted for hard facing, using the chromium-nickel-boron alloys which have become known as Colmonoy. More recently still, the cobalt-base Stellite alloys have also been used. These materials in powder form are sprayed on to the surface in the usual way. The deposit is afterwards heat treated by a torch, so that fusion takes place. The process is often known as spray-welding. Such coatings are primarily used for hard facing under wear conditions, but as the Anal surface is nickel-chromium or cobalt-chromium they exhibit very high anticorrosive properties. 

Stellite (Cabot Corp.) (or the equivalent), Colmonoy (Wall-Colmonoy Corp.) (or the equivalent), Type 3 tungsten carbide, etc. overlay-weld deposit of 0.8 mm (0.030 in.) minimum finished thickness, or, if available, a solid cast part of equal material may be substituted. 

It is found that from induced activity and dose rate considerations, stellite can be replaced by either Colmonoy-6 or Tribaloy-700. Based on fast reactor experience with colmonoy, colmonoy has been chosen. An approximate estimate of the shield requirement assuming a permissible dose rate of 100 mR/h have been worked out. In the following discussions, as the basic SS component itself becomes radioactive and requires shielding, reduction in shield thickness is with respect to the minimum shielding required for the SS component [5]. 

Trademark of Wall Colmonoy Corp. 4. Trademark of Metallurgical Industries Inc. 

Colmonoy, Hard-surfacing alloys. Wall Col money... 

Sprayset, Organic peroxide catalyst, Witco Cop., Polymer Chemicals Group Spraywelder, Hard-surfacing application system, Wall Colmonoy Corp. 

The screw flights are welded with a hardfacing material such as Colmonoy 56 or Stellite 12 ... 

These characteristics lead to high quality overlays without cracks, minimal porosity, and high hardness values. For instance, Colmonoy 56 PTA powder can he laser deposited with resulting hardness values in the low 60s Rc. The final thickness that can be achieved for crack sensitive materials ranges from 0.4 to 1.5 mm. The final thickness achievable for less crack sensitive materials like Stellite 6 is not limited because multi-layer deposits can be applied. This method can be used on new screws the use in rebuilding screws is evaluated on a case-by-case basis. See Table 8.10 for a comparision of different welding methods. 

Ferro-TIc (Iron) HC-250 Colmonoy 84 Triballoy T-700 Stellite 6H (severe wear) Stellite 6H (severe wear)... 

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