المواصفات القياسية لسبائك النحاس المستمر
ASTM B505 is the premier global standard for copper-base alloys produced by the continuous casting process. This manufacturing method ensures superior material density, uniform grain structure, and high pressure tightness, making these alloys the preferred choice for heavy-duty industrial bearings, bushings, and marine components.
1. Scope of the Standard
The ASTM B505 specification covers continuous cast products in the form of rods, bars, tubes, and shapes. Unlike sand casting (ASTM B148), continuous casting pulls molten metal through a water-cooled graphite die, resulting in a product with virtually no porosity and excellent machinability.
2. Most Common Alloys under ASTM B505
While ASTM B505 covers dozens of copper alloys, the following four represent the majority of global trade and industrial demand:
| UNS Alloy | Common Name | Principal Characteristics |
|---|---|---|
| C95400 | Aluminum Bronze 9C | Most popular general-purpose aluminum bronze; high strength and wear resistance. |
| C95800 | Alpha Nickel Al-Bronze | Optimized for superior corrosion resistance in seawater and brackish water. |
| C93200 | SAE 660 Bearing Bronze | The “gold standard” for general-purpose bushings; excellent anti-friction properties. |
| C86300 | High Mang. Bronze | Extreme high strength and hardness; used for extra heavy loads at low speeds. |
3. Chemical Composition (%)
Below are the standard chemical requirements for the two most sought-after Aluminum Bronzes under ASTM B505:
| عنصر | C95400 (Aluminum Bronze) | C95800 (Nickel Al-Bronze) |
|---|---|---|
| نحاس | 83.0 min | 79.0 min |
| الألومنيوم (آل) | 10.0 - 11.5 | 8.5 - 9.5 |
| الحديد (الحديد) | 3.0 - 5.0 | 3.5 - 4.5 |
| النيكل (ني) | 1.5 max (optional) | 4.0 - 5.0 |
| المنغنيز (من) | 0.50 كحد أقصى | 0.8 - 1.5 |
4. Mechanical Properties (Typical)
Continuous casting enhances the mechanical integrity of these alloys compared to sand-cast equivalents.
| ملكية | C95400 | C95800 | C93200 |
|---|---|---|---|
| قوة الشد (دقيقة) | 515 MPa (75 ksi) | 585 MPa (85 ksi) | 240 MPa (35 ksi) |
| قوة العائد (دقيقة) | 205 MPa (30 ksi) | 240 MPa (35 ksi) | 140 MPa (20 ksi) |
| Elongation (in 2″) | 12٪ | 15% | 10 ٪ |
| Brinell Hardness (Typical) | 170 HBW | 150 – 170 HBW | 70 HBW |
5. الخصائص الفيزيائية
| ملكية | Value (C95400 / C95800) |
|---|---|
| سمك 12-300 مم × عرض 200-2300 مم | 7.45 – 7.64 g/cm³ (0.269 – 0.276 lb/in³) |
| نقطة الانصهار (السائل) | 1027°C – 1060°C (1880°F – 1940°F) |
| توصيل حراري | 33 – 59 W/m·K |
| Coefficient of Expansion | 16.2 x 10⁻⁶ /K |
6. Fabrication & Technical Characteristics
- القدرة على التصنيع: Excellent. Most ASTM B505 alloys provide a smooth finish with high speed-feed rates.
- قابلية اللحام: Generally good for Gas Shielded Arc Welding (MIG/TIG), particularly for the aluminum bronze series.
- Non-Sparking: These alloys do not produce sparks upon impact, making them critical for safety tools and equipment in explosive environments (Oil & Gas).
- Pressure Tightness: The continuous cast process creates a highly dense matrix, ideal for components holding hydraulic fluids or high-pressure steam.
7. Primary Applications
- Industrial Heavy Machinery: Wear plates, gears, worm wheels, and high-load bushings.
- Marine Engineering: Seawater pump components, valve bodies, propeller nuts, and marine fasteners.
- Oil & Gas: Blowout preventer (BOP) parts, drill collars, and non-sparking safety components.
- Automotive/Transport: Transmission parts and steering mechanisms.
8. Quality Compliance
Material produced under ASTM B505 should be accompanied by a Mill Test Certificate (MTC) confirming:
- Full chemical analysis per heat.
- Mechanical testing (Tensile, Yield, Elongation).
- Dimensional inspection according to standard tolerances.
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