Concrete Mixer Blades
Industry: Cement concrete production.
Concrete Production: Cement powder, water, resins, sand and crushed stones, are mixed together before to be carried-out by special trucks.
Problem: During mixing, blades are subject to severe abrasion from the concrete, wear reduces thus the thickness of the blades up-to breakage. The concrete production center can not be subject to production stop during mixing because it will cause the further solidification of the concrete.
Service Conditions:
- Ambient temperature ~20°C to 50°C.
- Medium corrosion environment.
- Severe abrasion from the cement.
- Risk of shocks.
Caution: Usually, the blades of the mixer are manufactured from Chromium cast iron. Due to the low thermal expansion coefficient, the Cr-Cast Iron cannot be directly brazed thanks to the TufCote®. New mixing blades should be manufactured with a construction steel and then brazed with the TufCote®.
Coating Solution: TufCote® Abrasion resistant coating: Tungsten carbide with a metal matrix; 5 mm thickness. Use specifically the TufCote® Grade A 8mm ⌀ (even 6.35mm).
Benefits of the TufCote®:
- TufCote® extends the life time 3 times more than Cr cast iron.
- Simplicity, easy learning of the brazing procedure make it a possible application on site or in job shop.
- No capital investment is required to apply the TufCote® brazing flexible cord (only a flame torch is required).
- Expensive steels are not required to manufacture the blades.
- Possibility to rebuilt on a coating previously welded.
- Coarse and angular tungsten carbide grains, for better resistance to abrasion (TufCote® Grade A).
TufCote® Application Procedure:
Preparation of the Piece
- Surface must be cleaned and free of surface contamination.
- All edges must be cut by grinding.
Preheating of the Area
- With oxy-acetylene torch, preheat the piece area to 450°C (840°F).
Prime Cote (if required)
PRIME COTE under layer might be applied about 300μm thick.
- To avoid oxidation of surface.
- To increase TufCote® bonding.
Hard-facing Operation
- The torch flame must form an angle of about 45° with the piece surface to be hard-faced, and TufCote® at a 45° angle to the same surface.
- The flame must swing from side to side of the weld cladding.
- TufCote® is then fed through the holder 4-6” at a time.
- The tip of the cord should not be lowered or lifted during fusion.
- Speed of cladding is ~2Kg/h.
TufCote® GA Specification:
- Self Fluxing Matrix: 37 to 40%W.
- Tungsten Carbides: 60 to 63%W, Particle Size: Grade A within 0.1 to 1.6mm (10-150 mesh).
- Packaging: Continuous flexible cord coiled on spool. Available diameter 4.75 or 6.35 or 8mm.