The strength of EA4T axles depends on their final heat treatment, geometry, and application (e.g., freight, passenger, or locomotive use). However, standard mechanical properties for EA4T steel axles after quenching and tempering are as follows:
Mechanical Strength of EA4T Axles
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 880 – 1080 MPa |
| Yield Strength (Rp0.2) | ≥ 700 MPa |
| Elongation (A5) | ≥ 12% |
| Reduction of Area (Z) | ≥ 45% |
| Charpy Impact Toughness | ≥ 35 J at -20°C (often > 40 J in practice) |
| Brinell Hardness (HBW) | 260 – 300 HB |
| Fatigue Strength | > 400 MPa (rotating bending, R = -1, unnotched) |
| Fracture Toughness (KIC) | High (material designed for critical sections) |
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Fatigue resistance is one of EA4T's standout features, making it ideal for high-cycle loading applications like axles under locomotives or passenger trains.
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These properties meet or exceed international standards such as:
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EN 13261 (European standard for railway axles)
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UIC 811-1
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TB/T 2344 (Chinese axle standard)
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Example Applications:
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High-speed passenger train axles (150–250 km/h)
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Locomotive axles under >22.5-ton axle loads
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Heavy-duty metro or EMU axles
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EA4T is designed for:
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High-speed trains
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Heavy-haul locomotives
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Long service life under fatigue loads
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Higher Machining Difficulty
EA4T, being a tough and hard steel, causes:
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More tool wear
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Longer machining cycles
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Higher cutting force requirements
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1. Superior Alloy Composition
EA4T contains higher amounts of alloying elements like chromium (Cr) and molybdenum (Mo), which enhance:
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Fatigue resistance
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Wear resistance
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Hardenability
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Strict Heat Treatment Requirements
EA4T shafts require:
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Precisely controlled quenching and tempering
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Uniform mechanical properties across the entire cross-section
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Avoidance of over-tempering or grain growth
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