Alloy 28
Material
Alloy 28, 28Cr, UNS N08028, W.Nr. 1.4563
Overview
Alloy 28 is a cold hardened nickel-based alloy intended for corrosion resistance in highly sour (H2S) environments with moderate chloride content, requiring high strength up to 350°F. Alloy 28 offers increased resistance to the effects of H2S relative to stainless steels allowing its use as downhole tubular components, packers, and other subsurface equipment in sour wells with high-pressure and high-temperature (HPHT) conditions and Acid Gas Injection (AGI) wells. In addition, it has a high resistance to pitting and crevice corrosion in the presence of chlorides. However, all environmental factors, including H2S, CO2, temperature, pH, and chloride concentration, should be considered before final material selection.
Application
Alloy 28 is used in the chemical and petrochemical processing industry. Alloy 28 tubes are cold worked to high strength levels for downhole service in moderately corrosive deep sour gas wells.
Chemical composition
| Material | Fe | Ni | Cu | Cr | Mo |
|---|---|---|---|---|---|
| Alloy 28 | Balance | 30.0-34.0 | 0.6-1.4 | 26.0-28.0 | 3.0-4.0 |
| Material | C | Mn | Si | P | S |
| Alloy 28 | ≤0.03 | ≤2.5 | ≤1.0 | ≤0.030 | ≤0.030 |
Mechanical property
Alloy 28 in the solution annealed condition as per ASTM B668
| Material | Tensile strength ksi (MPa) |
Yield strength at 0.2 offset ksi (MPa) |
Elongation in 2” % min. |
|---|---|---|---|
| N08028 | ≥73 (500) | ≥31 (214) | ≥40 |
Available Process
Cold worked and bright annealed
Cold worked, bright annealed, polished (MP, EP etc.)
Common Tests
- ◎ Chemical composition
- ◎ Tension
- ◎ Hardness
- ◎ Flaring
- ◎ Flange
- ◎ Flattening
- ◎ Micro structure
- ◎ Hydrostatic
- ◎ NDT
- ◎ Intergranular Corrosion
- ◎ Surface condition
- ◎ Shape and dimension
- ◎ Positive Material Identification
Product forms
Capillary tube
- ◎ OD 0.30 ~ 3.0 mm
- ◎ WT 0.05 ~ 0.5 mm
Precision seamless tube
- ◎ OD 3.0 ~ 89 mm
- ◎ WT 0.10 ~ 10.0 mm
HP / UHP BA+ tube
- ◎ OD 3.0 ~ 76 mm
- ◎ WT 0.10 ~ 10.0 mm
Service
- ◎ Precision cutting
- ◎ Tube surface treatment, like ID surface super mirror polishing, best level could reach Ra0.0015um
- ◎ Tube deep processing, like coiling, bending, end forming, body forming, laser processing, various needles processing, built to drawing and sample, etc.