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The BHD process is not a coating, heat treatment or other form of mechanical, chemical or alloying bonding to the surface like plasma impingement. The process diffuses into the host material to form an inter-metallic structure which improves the resistance to impact, wear, corrosion and erosion as required by the specific application for:
- Boiler Feedwater Startup
- Boiler Feedwater
- Regulator
- Condensate Recirculation
- Deaerator Level Control
- Reheat Spray
- Desuperheater
- Turbine Bypass & Dump
Technical Data
- Hardness: 1600-2500 KHN (KNOOP), dependent upon base material
- Wear Resistance: Excellent against all hard surfaces
- Corrosion Resistance: Excellent against HCL, H2SO4, HF, salt water and molten salts
- Coefficient of Friction: Approximately 33% of base material
- Gas Barrier: Excellent against oxygen, hydrogen and H2S
- Surface Finish: The surface finish will remain unaltered and tolerance changed less than 0.001”
- Penetration: Up to 0.040” depending on the base material, penetration is uniform and continuous
- Masking: Surfaces not requiring the processes e.g. threads or welding ends, may be masked
Hardness Values
There are several methods of testing the hardness of metals. The method used is based upon the anticipated hardness, metallurgy, temperature and geometry of the component. To compare the results of one method over another is difficult, however the following table lists approximate comparisons of various materials. The hardness values for diffusion hardening is dependent upon the base metal.
| Material | Rockwell C | Knoop |
|---|---|---|
| Alloy 20 | 10 | 180 |
| 304 St. St. | 10 | 180 |
| 316 St. St. | 14 | 190 |
| Hastelloy B | 14 | 190 |
| Nickel | 16 | 195 |
| Hastelloy C | 20 | 210 |
| 17-4 Nace | 28-32 | 320 |
| Monel | 20-35 | 350 |
| Alloy 25 | 30 | 320 |
| CA6NM | 30 | 320 |
| Inconel | 36 | 355 |
| 17-4 ph | 30-41 | 400 |
| Stellite 6 | 40-46 | 500 |
| 416 St. St. | 45 | 500 |
| 440C St. St. | 50-60 | 700 |
| Stellite 12 | 47-51 | 600 |
| Stellite 1 | 51-58 | 660 |
| Colmonoy 6 | 56-61 | 700 |
| Tungsten Carbide | 70-75 | 1000-1200 |
| Ceramics | 70-75 | 1000-1200 |
| Hard Chrome Plate | 65-72 | 920-1100 |
| BHD Process | 81+ | 1500-2500 |