Hastelloy G-2
Supplied by Huaxiao-Alloy – Your Trusted Global Alloy Partner
1. Introduction to Hastelloy G-2
Hastelloy G-2 is a nickel-chromium-iron-molybdenum alloy designed to provide superior resistance in phosphoric acid and complex chemical environments. Compared to traditional stainless steels and many nickel alloys, Hastelloy G-2 exhibits outstanding resistance to oxidizing as well as reducing conditions, making it one of the most versatile corrosion-resistant alloys available.
Its unique composition allows it to withstand strong oxidizers such as nitric acid, while also resisting reducing agents such as hydrochloric and phosphoric acids. This dual resistance makes it an excellent choice for fertilizer production, acid reactors, pollution control systems, and nuclear fuel reprocessing.
At Huaxiao-Alloy, we supply Hastelloy G-2 in a wide range of product forms including sheets, plates, coils, bars, rods, tubes, pipes, wires, and custom components. Our materials comply with ASTM, ASME, and international standards, ensuring quality and reliability for global projects.
2. Chemical Composition of Hastelloy G-2
| Element | Typical Content (wt%) | Function |
|---|---|---|
| Nickel (Ni) | Balance | Corrosion resistance and toughness |
| Chromium (Cr) | 21–23 | Oxidation and corrosion resistance |
| Iron (Fe) | 18–21 | Structural balance and strength |
| Molybdenum (Mo) | 6–8 | Resistance to reducing acids |
| Copper (Cu) | 1.5–2.5 | Enhances phosphoric acid resistance |
| Cobalt (Co) | ≤2 | Trace element |
| Manganese (Mn) | ≤1 | Deoxidizer |
| Silicon (Si) | ≤1 | Strengthener |
| Carbon (C) | ≤0.02 | Low content prevents carbide precipitation |
| Phosphorus (P) | ≤0.04 | Controlled impurity |
| Sulfur (S) | ≤0.03 | Controlled impurity |
This chemistry makes Hastelloy G-2 highly resistant to phosphoric acid in both pure and contaminated conditions, while also providing outstanding structural stability under severe chemical exposure.
3. Mechanical Properties of Hastelloy G-2
| Property | Typical Value |
|---|---|
| Density | 8.3 g/cm³ |
| Melting Range | 1340–1380 °C |
| Tensile Strength | 760 MPa |
| Yield Strength (0.2 percent offset) | 350 MPa |
| Elongation | 40 percent |
| Hardness | 85 HRB |
These mechanical properties allow Hastelloy G-2 to maintain strength, ductility, and workability, even when exposed to extreme industrial environments.
4. Key Features of Hastelloy G-2
Exceptional resistance to phosphoric acid, even when contaminated with chlorides and fluorides.
Outstanding performance in both oxidizing and reducing environments.
Excellent resistance to nitric acid and mixed acid solutions.
Good mechanical strength combined with fabrication flexibility.
Maintains corrosion resistance after welding and forming.
Long service life in fertilizer, chemical, and pollution control industries.
5. Heat Treatment
Hastelloy G-2 is typically solution heat treated at 1175 °C followed by rapid quenching.
This process restores corrosion resistance after cold working or welding.
Heat treatment also improves ductility and reduces residual stresses.
6. Applications of Hastelloy G-2
6.1 Fertilizer Industry
Processing equipment for phosphoric acid production.
Fertilizer reactors and evaporators exposed to wet-process phosphoric acid.
6.2 Chemical Processing
Heat exchangers handling nitric, phosphoric, and hydrochloric acid mixtures.
Pumps, valves, and piping systems in mixed chemical streams.
6.3 Pollution Control
Flue gas desulfurization units.
Waste treatment plants handling acidic industrial effluents.
6.4 Nuclear Applications
Components exposed to nuclear fuel reprocessing streams.
Resistance to oxidizing-reducing cycles ensures durability in nuclear facilities.
6.5 Marine and Offshore
Equipment exposed to chloride-rich environments.
Heat exchangers and pumps in seawater-cooled systems.
7. Advantages of Hastelloy G-2
Balanced performance in both oxidizing and reducing conditions.
Excellent resistance to wet-process phosphoric acid with impurities.
Strong fabrication properties, allowing welding and forming.
Long-term cost savings due to extended service life.
Availability in multiple product forms at Huaxiao-Alloy.
8. Limitations of Hastelloy G-2
Higher cost compared to stainless steels.
Requires careful design to avoid crevice corrosion in stagnant solutions.
Limited availability compared to more common nickel alloys.
9. Comparison with Other Alloys
| Alloy | Strengths | Weaknesses | Applications |
|---|---|---|---|
| Hastelloy G-2 | Strong in phosphoric acid, balanced oxidizing/reducing resistance | Higher cost, limited stock | Fertilizer, nuclear |
| Hastelloy G-3 | Better resistance to oxidizing environments | Slightly less reducing acid resistance | Pollution control, chemical plants |
| Hastelloy C-22 | Excellent oxidizing resistance | Less phosphoric acid resistance | Chemical and marine |
| Stainless Steel 316L | Low cost, good general corrosion resistance | Fails in strong acids | General processing |
| Inconel 625 | High strength, seawater resistance | Not optimized for phosphoric acid | Offshore, aerospace |
10. Standards and Specifications
UNS: N06985
W. Nr.: 2.4619
Standards:
ASTM B333 – Plate, Sheet, Strip
ASTM B336 – Forged fittings
ASTM B622 – Seamless Pipe and Tube
ASTM B619 – Welded Pipe
ASTM B366 – Fittings
11. Product Forms Available at Huaxiao-Alloy
Plates and sheets
Strips and coils
Bars and rods
Seamless and welded tubes
Pipes and fittings
Wires and electrodes
Forgings and custom-machined components
12. Fabrication and Processing
Forming: Good hot and cold forming properties.
Welding: Excellent weldability with GTAW, GMAW, and SMAW methods.
Machining: Work hardens quickly; requires sharp tools and slow feeds.
Cleaning: Use mild acids for pickling; avoid oxidizing agents.
13. Why Choose Huaxiao-Alloy for Hastelloy G-2?
ISO 9001 certified supplier with global reach.
Large inventory of Hastelloy G-2 in multiple dimensions.
Custom cutting, machining, and fabrication services.
Expert support for material selection and design optimization.
Fast worldwide delivery with competitive pricing.
📩 Contact us today at [email protected]
📱 WhatsApp: +1 (579) 300-2733
It is widely used in phosphoric acid production, chemical processing, and nuclear fuel reprocessing.
Hastelloy G-2 is optimized for phosphoric acid resistance, while G-3 performs better in oxidizing conditions.
Yes, it has good weldability when proper filler metals are used.
Yes, it offers good performance in chloride-rich marine environments.
We supply plates, sheets, bars, tubes, pipes, wires, and fittings.
15. Conclusion
Hastelloy G-2 is a highly specialized nickel-chromium-molybdenum-iron alloy with unmatched resistance to phosphoric acid and mixed acid environments. Its dual resistance to oxidizing and reducing chemicals makes it one of the most versatile alloys for the fertilizer, chemical, pollution control, nuclear, and marine industries.
At Huaxiao-Alloy, we are committed to delivering high-quality Hastelloy G-2 products in various forms to meet the exacting demands of our global clients. With strong technical expertise and fast delivery, we ensure your projects achieve both performance and cost-efficiency.
📩 Email: [email protected]
📱 WhatsApp: +1 (579) 300-2733
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