Beta C (UNS R58640, Gr19, GB TB9)

1. Exceptional strength and specific strength (core advantage): Tensile strength in solution-treated and aged condition is ≥ 1170 MPa (exceeding 1400 MPa under certain conditions), significantly higher than Gr5 (TC4). Its specific strength (≈ 260 kN·m/kg) far surpasses that of stainless steels and most nickel-based alloys.
2. Excellent fracture toughness and stress corrosion cracking resistance: K_IC can reach 40-60 MPa·√m, with stress corrosion cracking resistance significantly superior to Gr5.
3. Superior hardenability: It can be fully hardened through a 300mm diameter cross-section, making it an ideal material for large-sized fasteners, large-diameter springs, and heavy structural components.
4. Good cold working performance: Cold drawing, cold rolling, cold bending, cold heading, and other cold working processes can be performed in the solution-treated state, with cold working performance better than Gr5.
5. Excellent corrosion resistance: It performs exceptionally well in seawater, chloride environments, and acidic oil and gas media containing H₂S/CO₂.
6. Complies with multiple international standards: ASTM B348, ASTM F136 (medical), ISO 5832-3, AMS 4957, GB/T 2965, etc.

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Continuous operating temperature (primarily for strength and thermal stability):
It is recommended to be ≤ 300°C, where the microstructure remains stable and performance degradation is controllable.
Short-term exposure temperature:
Can reach as high as 400°C, but strength and toughness will decrease.
Maximum design temperature for pressure-bearing structural components: Typically considered as 250-300°C, and performance verification is required based on specific stress levels.
High-temperature limitations:
Beta C is a metastable β-type titanium alloy. Prolonged exposure at 300-400°C may result in α-phase precipitation leading to embrittlement, so it is not recommended for long-term use in this temperature range. For long-term service at higher temperatures, TA15 (≤ 500°C) or Gr5 (≤ 400°C) are recommended.

The excellent hardenability of Beta C mainly stems from its high content of beta-stabilizing elements (V 8%, Cr 6%, Mo 4%):
1. Abundant beta-phase stabilizing elements: High contents of V, Cr, and Mo significantly lower the beta-to-alpha transformation temperature and delay the kinetics of phase transformation, allowing the alloy to fully retain the metastable beta phase during air cooling or oil quenching.
2. Extremely slow phase transformation rate: The beta-to-alpha transformation rate of Beta C is much lower than that of Gr5 (TC4). Even in large-section components (over Φ300mm), it can be fully quenched through, resulting in uniform mechanical properties.
3. Engineering significance: This enables Beta C to be used for manufacturing large-sized high-strength fasteners (e.g., M30 and above), large-diameter springs, and heavy structural parts. In contrast, Gr5 is limited by its hardenability, leading to poor performance uniformity in large-section applications.

The welding performance of Beta C is generally average, and strict adherence to the welding process specifications for beta titanium alloys is required:
1. Recommended welding methods: TIG (Tungsten Inert Gas welding), Electron Beam Welding, Laser Welding, and Resistance Welding.
2. Pre-welding preparation: The welding area must be strictly cleaned to remove oil, scale, and moisture.
3. Protective gas: High-purity argon gas (≥ 99.99%) should be used for welding and backside protection to prevent high-temperature oxidation contamination. Beta C is more sensitive to gas contamination than α+β titanium alloys.
4. Post-weld treatment: It is recommended to perform post-weld solution treatment (approximately 800-900°C, air cooling) and aging treatment to restore the strength and toughness of the β microstructure. For cold-worked materials, solution treatment should be performed before welding.
5. Filler metal: It is recommended to use filler wire of the same material as Beta C or β-C matching welding wire to ensure weld performance compatibility.
6. Key precautions: Brittle α phase precipitation may occur in the heat-affected zone of Beta C welding. It is recommended to strictly control the heat input (linear energy) and perform complete heat treatment after welding.

It can partially replace, especially in high-intensity and SCC-resistant service conditions:
Scenarios where Beta C is a suitable alternative (with clear advantages over Beta C):
Ultra-high-strength fasteners: Beta C offers strength more than 1.3 times that of Gr5, making it suitable for fasteners with higher load requirements.
Large-section structural components (>Φ50mm): Beta C exhibits significantly better hardenability than Gr5, making it suitable for large-sized parts.
Oil and gas downhole tools: Beta C's SCC resistance is notably superior to Gr5, making it suitable for acidic oil and gas environments.
High-stress springs: The strength level of Beta C makes it an ideal material for high-performance springs.
High-stress marine engineering components: Beta C outperforms Gr5 in terms of SCC and corrosion resistance.
Scenarios where it is not suitable as a substitute (Gr5 remains the better choice):
High-temperature components for long-term service above 400°C: Gr5 has a superior long-term operating temperature (≤ 400°C) compared to Beta C (≤ 300°C).
Complex welded structural parts: Gr5 exhibits better weldability than Beta C, with more mature post-weld heat treatment processes.
Cost-sensitive projects: Beta C, due to its higher number of alloying elements and more complex manufacturing processes, has a significantly higher cost than Gr5.
Projects with extreme lightweighting requirements (density-sensitive): Beta C has a higher density (4.82 g/cm³) than Gr5 (4.43 g/cm³).
Global supply chain universality requirements: Gr5 (TC4) is the most widely used titanium alloy worldwide, with more abundant procurement and processing resources available.
Material Selection Recommendations: Please provide detailed operating conditions (temperature range, load type, cross-sectional dimensions, welding requirements, medium environment, and service life) for specific material selection. We can assist with technical and economic comparative analysis to help you make the optimal choice between Beta C and other titanium alloy grades.
For quotations on specific specifications, material test reports, or technical parameter sheets, please contact our sales engineers. We support customizing dimensions, heat treatment conditions, and surface treatments as required, and provide a full set of internationally certified documents.