C63200
C63200 is a high nickel aluminum bronze alloy (UNS number). With the core advantages of “high strength × seawater corrosion resistance× cavitation corrosion resistance”, it replaces stainless steel and nickel-based alloy in extreme working conditions such as aerospace, marine and military industries. The following is systematically analyzed from six dimensions:
I. Standard System and Brand Code
1. Core implementation standards
- Deformed workpieces (bars/plates/tubes): ASTM B150 (American standard, regulating mechanical properties and inspection);
- Castings (turbines/propellers): ASTM B148 (American standard, covering sand casting/die – casting processes);
- Aviation – specific: AMS 4640 (aviation material standard, with stricter composition, suitable for engine components).
2. Global brand comparison
| System/Region | Grade | Description |
|---|---|---|
| American UNS | UNS C63200 | Core identification (high-nickel aluminum bronze) |
| European EN | CW306G | Equivalent to C63200 |
| Chinese National Standard | QAl9-4-4-2 (approximate) | Slightly lower nickel/manganese content, performance is close |
| Japanese JIS | CAC703 | Suitable for ship propeller applications |
II. Chemical composition (mass fraction%, ASTM standard)
C63200 achieves performance breakthrough through “five-element coordination of Cu-Al-Ni-Fe-Mn”, with precise elements:
| Element | Content range | Core role |
|---|---|---|
| Cu | Remaining amount (~85%) | Matrix, ensuring electrical/thermal conductivity and providing basic corrosion resistance |
| Al | 8.5 – 9.5 | Forming α+κ dual-phase structure, improving strength and hardness |
| Ni | 4.0 – 5.0 | Key corrosion-resistant element! Enhancing corrosion resistance to seawater/acidic media |
| Fe | 3.0 – 4.5 | Refining grains, precipitating Fe-Al phase, improving wear resistance |
| Mn | 1.0 – 2.0 | Improving hot workability and assisting in deoxidation |
III. Mechanical properties (heat treatment state)
The performance of C63200 is far superior to that of ordinary aluminum bronze (such as C63000) due to aging strengthening (κ phase precipitation);
| State | Tensile strength (MPa) | Yield strength (MPa) | Elongation (%) | Hardness (HB) | Core characteristics |
|---|---|---|---|---|---|
| Solution-treated state | ~650 | ~350 | ~25 | 180 – 200 | Easy to process (rolling, forging) |
| Aged state | 830 – 950 | 550 – 650 | 10 – 15 | 250 – 350 | Balanced strength and toughness (high-stress scenarios) |
Physical Properties:
- Density: 7.6 g/cm³ (only 80% of nickel – based alloys, significant lightweighting);
- Melting point: 1030 – 1060°C (short – term resistance to 700°C high temperature, such as aerospace engine components);
- Cavitation resistance: Better than stainless steel, suitable for high – speed fluid environments (such as propellers, pump impellers).
IV. Heat Treatment and Processing Requirements
- Solution treatment (refining structure):
- Temperature: 925 – 975°C (hold for 1 – 2 hours to dissolve alloying elements uniformly);
- Cooling: Rapid water quenching (inhibit the precipitation of coarse κ phase, retain fine dual – phase structure);
- Function: Lay the foundation for age strengthening and restore workability.
- Age strengthening (precipitation of κ phase):
- Temperature: 550 – 650°C (hold for 2 – 4 hours to precipitate dispersed κ phase and pin dislocations);
- Effect: Strength increases by more than 30%, hardness reaches HB 250 – 350 (wear resistance improves dramatically);
- Applicable scenarios: High – load bearings, gears, aerospace engine bushings.
- Machining and Welding:
- Machining: Medium cutting difficulty (similar to high – strength stainless steel), cemented carbide tools + high – lubricity cutting fluid, low speed and high feed rate are recommended;
- Welding: Preheat to 250 – 350°C (prevent cold cracks), use TIG welding (ERCuNiAl welding wire), and age treatment must be done after welding (restore strength and corrosion resistance).
V.Main Application Fields (Extreme Corrosion + High – Load Scenarios)
C63200, relying on “seawater resistance × cavitation resistance × high strength”, dominates the following fields (performance exceeds stainless steel, and the cost is only 1/3 of nickel – based alloys):
- Aerospace:
- Aircraft landing gear bearings, engine bushings (aged state, resistant to 300°C high temperature + high impact);
- Helicopter rotor hinges, high – pressure valves in hydraulic systems (resistant to cavitation + hydraulic oil corrosion).
- Shipbuilding and Marine Engineering:
- Propellers of submarines/warships, seawater pump casings (resistant to seawater scouring + cavitation, service life is twice that of copper alloys);
- Deep – sea drilling equipment (blowout preventers, underwater fasteners, resistant to seawater corrosion at a depth of 3000 meters).
- Military Industry and Energy:
- Gun recoil mechanisms, missile components (high impact + resistant to fuel gas corrosion);
- Nuclear power cooling pump components (resistant to high – temperature water + radiation, replacing stainless steel).
- Heavy Industrial Equipment:
- Rolling mill bearings, wear – resistant liners for mining machinery (high hardness + resistant to abrasive wear);
- Impellers of chemical pumps (resistant to mixed corrosion of hydrochloric acid/seawater, replacing Hastelloy).
Key Summary
- Core Advantages:
- Corrosion resistance: Corrosion rate in 3.5% NaCl solution is < 0.02 mm/a (better than 316L stainless steel);
- Mechanical properties: Strength exceeds 900 MPa after aging, close to nickel – based alloys;
- Cost – effectiveness: Performance reaches 80% of nickel – based alloys, while cost is only 1/3 of them.
- Limitations:
- High cold work hardening rate (multiple annealing processes required, increasing processing cost by 15%);
- Easy to cause galvanic corrosion when in contact with dissimilar metals (insulation treatment required).
C63200 is the “benchmark of high – nickel aluminum bronze”. It breaks through the performance bottleneck of ordinary aluminum bronze through five – element alloy design, and becomes the “ultimate replacement for stainless steel” in extreme working conditions such as aerospace, marine, and military industries, redefining the cost – effectiveness of corrosion – resistant and high – load materials.