Project Description
Introduction
N09945 (Incoloy 945) is a PH nickel-iron-chromium superalloy engineered for aggressive oil & gas sour service. Alloyed with Mo, Cu, Nb, Ti, and Al, it delivers high strength combined with outstanding resistance to SCC, SSC, pitting, and crevice corrosion in H₂S- and CO₂-rich environments. Approved under NACE MR0175 up to severity Level VII and Level VI-450°F.
Similar Grades
| Trade Name | UNS | Applicable Standards | Note |
|---|---|---|---|
| Incoloy 945X | N09946 | ASTM B637, API 6A Annex H | Higher-strength variant, YS ≥ 140 ksi |
| Incoloy 925 | N09925 | ASTM B805, B906, NACE MR0175 | Similar PH Ni-Fe-Cr, lower Cr |
| Inconel 718 | N07718 | ASTM B637, AMS 5663, AMS 5664 | Wider temp. range; less Cu |
| Inconel 725 | N07725 | ASTM B805, NACE MR0175 | Higher Mo, superior SCC resistance |
No established direct equivalents in EN, DIN, JIS, or GOST standards.
Applications
Oil & Gas — Downhole
Production tubing, casing collars, landing nipples, tool joints, packers, subsurface safety valves, expansion mandrels
Oil & Gas — Surface & Wellhead
Wellhead bodies, Christmas tree components, choke bodies, valve stems, tubing hangers, gate valves, flanges
Other Industries
Pump shafting, agitator shafts, heat exchanger tubing, subsea connectors, marine fasteners, chemical reactor vessels
Supply Forms & Sizes
| Form | Size Range | Remarks |
|---|---|---|
| Round Bar | Ø 12.7–560 mm | Hot-rolled, forged, cold-drawn |
| Hollow Bar | OD up to 660 mm | Custom bore dimensions |
| Flat Bar / Forged Flat | Width ≤ 300 mm | Custom thickness available |
| Plate | t 6–150 mm, W ≤ 2000 mm | Hot-rolled or forged |
| Seamless Tube / Pipe | OD 12.7–168 mm | ASTM B829 / API 5CT |
| Wire | Ø 0.1–10 mm | Coil or spooled |
Chemical Composition
Per ASTM B637 / UNS N09945 (wt%)
| Element | wt% | Element | wt% |
|---|---|---|---|
| Ni | 45.0–55.0 | Cu | 1.5–3.0 |
| Cr | 19.5–23.0 | Nb+Ta | 1.0–2.0 |
| Fe | Balance | Ti | 0.5–1.5 |
| Mo | 3.0–4.0 | Al | 0.01–0.50 |
| C | 0.005–0.040 | Mn | ≤ 1.00 |
| Si | ≤ 0.50 | S | ≤ 0.010 |
Mechanical Properties
Per ASTM B637 · Heat Treatment: Solution Anneal 1010–1066°C (WQ) + 1st Age 704–732°C / 6–8 h (FC) → 2nd Age 599–643°C, total ≥ 12 h (AC)
| Property | Standard Grade (125K) | Shaft Grade (Cold-Worked + DA) |
|---|---|---|
| UTS | ≥ 1035 MPa (150 ksi) | ≥ 1241 MPa (180 ksi) |
| YS (0.2%) | ≥ 862 MPa (125 ksi) | ≥ 1034 MPa (150 ksi) |
| Elongation | ≥ 15% | ≥ 10% |
| Hardness | ≤ 38 HRC (NACE limit) | ≤ 46 HRC |
| Reduction of Area | ≥ 20% | ≥ 15% |