Diffusion layer
Grows into the steel; no delamination.
Completions & production · Boronized SRP pump barrels
Boronized pump barrels that outlast coated barrels in sandy, corrosive wells
Diffused, not coated: the boronized layer is part of the metal.
Represented in Pakistan by Prestil Energy Pakistan
Snapshot
1,200–2,200HV hardness of the boronized bore
2–3×Longer sucker-rod pump run life (supplier-stated)
0.08 mmMinimum case depth (0.003 in)
9.75 mMaximum barrel length (32 ft)
Fe2B / FeBDiffusion layer, part of the metal, not a coating
H2S · CO2Also resists chlorides and produced water
Credentials
- Diffusion layer cannot peel, pit or flake like chrome plating
- Fine-honed bore and precision threads for stable plunger clearance
- Inspected for geometry, roughness, layer hardness and finish
- Direct replacement for chrome-plated barrels
Photo needed: micrograph of the boronized layer
Process
Diffused, not coated: how the boronized bore is made
- 1
Apply
Boron source on the bore
- 2
Diffuse
High-temperature furnace cycle
- 3
Clean
Remove residual compound
- 4
Finish
Fine hone and cut threads
- 5
Inspect
Geometry, roughness, hardness
Performance
Barrel surface hardness compared
Barrel surface hardness (HV)
Range from minimum to maximum, by surface treatment
Boronizing
1,200–2,200
Chrome plated
900–1,160
Nitriding
500–1,200
Ni-phosphate
600–1,100
Carbonitrided
653–760
View as table
| Surface treatment | Min HV | Max HV |
|---|---|---|
| Boronizing | 1,200 | 2,200 |
| Chrome plated | 900 | 1,160 |
| Nitriding | 500 | 1,200 |
| Ni-phosphate | 600 | 1,100 |
| Carbonitrided | 653 | 760 |
Corrosion resistant
Inert to H2S, CO2, chlorides, brine.
Low friction
Less wear in the plunger–barrel zone.
Also in Artificial Lift