| Process | Guidelines | |---------|------------| | | Best performed in the annealed condition. Cold working beyond 20 % strain may cause cracking in the hardened states. | | Welding | Pre‑heat not required for thickness ≤ 12 mm. Recommended filler metals: ER308L , ER309L , ER316L for corrosion‑critical zones, or EPRI‑17‑4 filler for matching alloy. Post‑weld heat treat (solution anneal + aging) restores strength. | | Machining | Good machinability in annealed state; H900 is tougher and may require carbide tooling, low feed, high rpm, and ample coolant. Typical cutting speeds: 60–90 m/min (HSS) → 150–200 m/min (carbide). | | Heat‑treatment after machining | If final dimensions are critical, perform solution anneal → water quench → age after machining to avoid distortion. | | Surface finish | Polished to < 0.2 µm Ra for critical corrosion zones; standard 120‑grit (Ra ≈ 2 µm) is adequate for most mechanical parts. |
| Temper | Tensile Strength (ksi) | Yield Strength (0.2% offset, ksi) | Elongation (%) | Hardness (HRC) | |--------|------------------------|------------------------------------|----------------|----------------| | AT | 120–140 | 105–125 | 8–15 | 28–35 | | XT | 150–180 | 140–170 | 3–8 | 36–42 | | XT UTS (special) | Up to 200 | Up to 185 | ~2 | ~44 | uns c72900 c729
. Unlike standard alloys that require rapid quenching, this material undergoes a phase transformation that creates a nanostructure of nickel and tin. This results in: Extreme Strength: Yield strengths ranging from 100 to 180 ksi (690 to 1241 MPa) [3, 7]. Anti-Galling: Exceptional lubricity and wear resistance, making it ideal for moving parts that might otherwise seize up [4, 8]. Non-Sparking & Non-Magnetic: Safe for use in explosive environments like gas rigs [4, 8]. Toxicity-Free: It is a leading replacement for beryllium copper, offering similar performance without the health risks associated with beryllium dust [2, 12]. 2. Key Performance Attributes Property Performance Benefit Corrosion Resistance Resists most sour (H2S), CO2, and acidic environments; immune to hydrogen embrittlement [5, 12]. Thermal Stability Retains strength at both cryogenic temperatures (-193°F) and elevated heat (up to 572°F) [5, 12]. Machinability Known for excellent machinability compared to other high-strength nickel alloys [4, 8]. 3. Critical Industrial Applications Because it thrives under severe loading and corrosive conditions, C72900 is a "problem-solver" alloy in several sectors: Aerospace: Used for landing gear bushings and aircraft bearings because it won't gall under high pressure [3, 7]. Oil & Gas: Found in | Process | Guidelines | |---------|------------| | |
The alloy achieves its unique properties through a specific balance of copper, nickel, and tin. Content (%) 14.5 – 15.5% Tin (Sn) 7.5 – 8.5% Copper (Cu) Balance (min. 77%) Iron (Fe) Zinc (Zn) Others (Mg, Mn, Cb, Pb) Traces (total < 0.5%) Sources: AZoM , AMETEK . 2. Key Physical & Mechanical Properties Recommended filler metals: ER308L , ER309L , ER316L