ASTM B572 Hastelloy X, a nickel-chromium-molybdenum-iron superalloy formally designated as UNS N06002, is a basic material in the aerospace and industrial gas turbine sectors.
This article provides a comprehensive overview of ASTM B572 Hastelloy X technical parameters and price.
What Is ASTM B572?
The American Society for Testing and Materials standard B572 specifically covers nickel-chromium-molybdenum-iron rods, which includes the chemical composition, physical properties, and testing requirements for UNS N06002.
Adherence to this standard is non-negotiable for critical applications, ensuring the material possesses the required metallurgical integrity.
ASTM B572 ensures that the Hastelloy X material is delivered in the solution annealed condition unless otherwise agreed, a state vital for optimal ductility and high-temperature performance.
Compliance guarantees the Hastelloy X rods for reliable use in high-stress thermal environments.
ASTM B572 Hastelloy X Parameters
Chemical Composition
The performance of Hastelloy X is derived from its chemical composition, as specified in ASTM B572.
Key compositions are:
- Nickel (Ni): The balance material, providing a stable, high-temperature matrix.
- Chromium (Cr): Approximately 20.5% - 23.0%, offering outstanding oxidation and sulfidation resistance up to 1240℃.
- Molybdenum (Mo): 8.0% - 10.0%, contributing to solid-solution strengthening and resistance to chlorine attack.
- Iron (Fe): 17.0% - 20.0%, a significant component that helps balance cost and properties without compromising high-temperature capabilities.
Deviation from these strict ranges can severely impact the alloy's performance, especially in aerospace components where consistency is paramount.
Mechanical Properties
The minimum mechanical properties for Hastelloy X rods must be verified through rigorous testing outlined in ASTM B572.
The required values in the solution-annealed condition are:
- Minimum Tensile Strength: Typically 110 ksi (758 MPa).
- Minimum Yield Strength: Typically 45 ksi (310 MPa).
- Minimum Elongation: 35%.
These properties ensure the material can withstand high static and dynamic loads within a heat-treating furnace or gas turbine.
ASTM B572 covers round, square, hexagonal, and rectangular rods and bars. The tolerances are critical for machining into finished aerospace components.
Common forms include hot-finished, cold-drawn, or turned finishes, chosen based on the desired surface quality and final part dimensions.
ASTM B572 Hastelloy X Rods Applications
1. Aerospace and Gas Turbines: Used for combustion cans, jet engine tailpipes, and afterburner components. The high creep-rupture strength is crucial here.
2. Heat Treating Industry: Frequently used for furnace muffles, retorts, fixturing, and radiant tubes where high-purity atmospheres and 2000°F temperatures are common.
3. Petrochemical and Power: Used in flare stack tips and high-temperature reactors where resistance to flue gas corrosion (including sulfur and chlorine) is required.
The reliability of the ASTM B572 standard underpins the safety and efficiency of all these critical high-temperature alloy applications.
Hastelloy X Rods Price
The price of ASTM B572 Hastelloy X Rods is a complex calculation influenced by several factors.
1. Raw Material Surcharge (RMS): The most significant variable. As a Nickel-Chromium-Molybdenum-Iron alloy, the global market price for nickel, chromium, and molybdenum dictates a large portion of the final cost. These prices fluctuate daily, leading to constant adjustment in alloy surcharges.
2. Production Volume and Form: The cost per pound is generally higher for smaller diameter rods and smaller lot sizes. Custom forging or specific surface finishes add to the complexity and therefore, the price.
3. Certification and Testing: The requirement for full ASTM B572 compliance, including non-destructive testing like ultrasonic inspection or dye penetrant testing, adds cost. Higher-tier certifications, such as aerospace component quality assurance, also increase the premium.
Global Supply Chain: Sourcing from specialized global factories affects logistics and tariffs. Savvy buyers often seek suppliers capable of consistently providing the solution annealed UNS N06002 material while mitigating raw material price volatility.
ASTM B572 Hastelloy X Rods Manufacturing Process
Melting and Refining:
First, high-purity raw materials are melted in a vacuum induction furnace to form an alloy. To ensure a uniform alloy composition and a clean, impurity-free interior, secondary refining techniques such as electroslag remelting or vacuum arc remelting are often used to further refine the material.
Hot Working and Primary Forming:
The refined alloy ingot is heated to extremely high temperatures to impart excellent ductility. Subsequently, the ingot is repeatedly processed in a large-tonnage forging machine or hot rolling mill to form the initial shape of the bar.
Rolling and Cold Working:
After cooling, the rough billet enters the rolling mill for precision rolling to near-final dimensions. For bars requiring higher dimensional accuracy or a smoother surface, cold working techniques such as cold drawing or peel grinding are employed. Cold working not only improves dimensional accuracy but also further enhances the material's strength and hardness.
Solution Annealing Heat Treatment:
This is the most critical step and a core requirement of the ASTM B572 standard. The bar is heated to approximately 1177°C and held for a sufficient period of time. Subsequently, rapid cooling is required to ensure Hastelloy X achieves maximum corrosion resistance, highest ductility, and most stable high-temperature properties.
Finishing and Certification:
The annealed bars are straightened, cut, and surface-treated to meet customer requirements. Finally, according to ASTM B572, the bars undergo rigorous chemical composition analysis, tensile strength testing, and non-destructive testing. Once all performance requirements are met, an MTR is issued and the product is released.
Conclusion
Hastelloy X Rods manufactured to ASTM B572 are indispensable for applications demanding exceptional performance at elevated temperatures.
The technical parameters defined by UNS N06002 ensure a minimum level of high tensile strength and oxidation resistance.
When procuring this high-temperature alloy, buyers must prioritize verified ASTM B572 compliance over minimum price.
