Hastelloy C-4
Supplied by Huaxiao-Alloy – Your Trusted Global Alloy Partner
1. Introduction to Hastelloy C-4
Hastelloy C-4 is a nickel chromium molybdenum alloy specifically designed for exceptional corrosion resistance in strong oxidizing and reducing environments. Unlike many conventional nickel alloys, Hastelloy C-4 exhibits outstanding stability at high temperatures and maintains its corrosion resistance after long-term exposure between 650 and 1040 °C.
This alloy is widely used in the chemical processing, pharmaceutical, pollution control, and power generation industries. Thanks to its controlled composition, Hastelloy C-4 provides excellent resistance to stress corrosion cracking, intergranular corrosion, and pitting, even in harsh chemical media.
At Huaxiao-Alloy, we supply Hastelloy C-4 in sheets, plates, bars, tubes, wires, and customized machined parts. We work with clients worldwide to provide tailor-made solutions for highly demanding applications.
2. Chemical Composition of Hastelloy C-4
| Element | Typical wt.% | Function |
|---|---|---|
| Nickel (Ni) | Balance | Base element, corrosion resistance |
| Chromium (Cr) | 14–18 | Improves oxidation resistance |
| Molybdenum (Mo) | 14–17 | Enhances resistance to pitting and crevice corrosion |
| Iron (Fe) | ≤3 | Balances structure |
| Cobalt (Co) | ≤2 | Minor strengthening effect |
| Tungsten (W) | ≤2 | Improves localized corrosion resistance |
| Manganese (Mn) | ≤1 | Deoxidizer |
| Silicon (Si) | ≤0.08 | Controlled for corrosion performance |
| Carbon (C) | ≤0.015 | Very low carbon to prevent sensitization |
| Vanadium (V) | ≤0.35 | Stabilizes microstructure |
The low carbon content ensures that Hastelloy C-4 remains resistant to grain boundary precipitation, making it suitable for use after welding without the risk of intergranular attack.
3. Mechanical Properties of Hastelloy C-4
| Property | Value |
|---|---|
| Density | 8.64 g/cm³ |
| Melting Range | 1325–1370 °C |
| Tensile Strength (Room Temp) | 690–760 MPa |
| Yield Strength (0.2 percent offset) | 275–310 MPa |
| Elongation | 40–50 percent |
| Hardness | 85–90 HRB |
These values demonstrate Hastelloy C-4’s balance of strength, ductility, and toughness, making it reliable in both ambient and elevated temperature conditions.
4. Key Features of Hastelloy C-4
Excellent stability at high temperatures between 650–1040 °C.
Resistance to pitting, crevice corrosion, and stress corrosion cracking.
Low carbon content prevents sensitization during welding.
Superior corrosion resistance in oxidizing and reducing environments.
Retains ductility after prolonged high-temperature exposure.
Easy fabrication, including welding and forming, without post-weld heat treatment.
5. Heat Treatment
Hastelloy C-4 is usually delivered in the solution-annealed condition.
Solution annealing: 1065–1175 °C, rapid cooling (quenching).
Heat treatment ensures maximum corrosion resistance and mechanical ductility.
The alloy should not be exposed to prolonged service at 650–1040 °C without proper consideration, although it is more stable in this range compared with many other Hastelloy grades.
6. Applications of Hastelloy C-4
6.1 Chemical Processing
Reactors and heat exchangers handling strong oxidizing agents.
Equipment used in phosphoric acid production.
Components in chlorination systems.
6.2 Pollution Control
Flue gas scrubbers
Incinerator components
SOâ‚‚ absorber systems
6.3 Pharmaceutical and Food Processing
Equipment requiring corrosion resistance against aggressive cleaning agents.
Reactors and mixers for pharmaceutical intermediates.
6.4 Power Generation
Heat exchangers exposed to high-temperature oxidizing environments.
Nuclear industry applications requiring structural stability.
6.5 Other Applications
Marine engineering systems exposed to seawater.
Components in pulp and paper bleaching operations.
7. Advantages of Hastelloy C-4
Retains corrosion resistance after welding without heat treatment.
Exceptional resistance to chlorides and oxidizing chemicals.
Maintains toughness and ductility under prolonged service.
Strong resistance to intergranular corrosion even after thermal cycling.
Suitable for critical applications in nuclear, chemical, and marine environments.
8. Limitations of Hastelloy C-4
More costly compared with stainless steel and standard nickel alloys.
Availability may be limited compared with other Hastelloy grades.
Requires careful machining techniques due to work hardening.
9. Comparison with Other Alloys
| Alloy | Strengths | Limitations | Applications |
|---|---|---|---|
| Hastelloy C-4 | Excellent stability at 650–1040 °C | Higher cost | Chemical reactors, pollution control |
| Hastelloy C-22 | Superior resistance to oxidizing acids | Less stable at high temp | Chemical and flue gas cleaning |
| Hastelloy C-276 | Strong in reducing environments | Lower high-temp stability | Petrochemical, marine |
| Inconel 625 | Weldable, corrosion resistant | Less oxidation resistance | Aerospace, marine |
| Titanium Gr.2 | Excellent corrosion resistance | Limited to lower temperatures | Heat exchangers, desalination |
10. Standards and Specifications
UNS Number: N06455
W. Nr.: 2.4610
Standards:
ASTM B622 (Seamless Pipe and Tube)
ASTM B626 (Welded Pipe and Tube)
ASTM B575 (Plates, Sheets, Strips)
ASTM B619 (Welded Pipe)
ASTM B622/B626/B619/B775 (General Requirements)
11. Product Forms Supplied by Huaxiao-Alloy
Huaxiao-Alloy supplies Hastelloy C-4 in:
Plates, Sheets, Strips
Bars and Rods
Pipes and Tubes (Seamless and Welded)
Welding Wire and Electrodes
Forgings and Fittings
Custom Machined Parts
Each product is supplied with mill test certificates, third-party inspection options, and international packaging standards.
12. Fabrication and Processing
Forming: Hot forming at 1175 °C, followed by rapid cooling. Cold forming requires intermediate annealing.
Welding: GTAW, GMAW, and SMAW methods are effective. Filler metals include Hastelloy C-4 and C-22.
Machining: Requires rigid tools and slow speeds due to work hardening.
Heat Treatment: Solution annealed before use for maximum corrosion resistance.
13. Why Choose Huaxiao-Alloy for Hastelloy C-4
Extensive global inventory of Hastelloy C-4 products.
ISO 9001 certified quality management system.
Strong technical support from an experienced metallurgical team.
Custom processing, cutting, and machining services.
Fast delivery and competitive pricing to meet urgent demands.
📩 Email: [email protected]
📱 WhatsApp: +1 (579) 300-2733
Hastelloy C-4 provides better high-temperature stability in the 650–1040 °C range, while C-22 offers higher resistance to oxidizing acids and C-276 excels in reducing environments.
Yes, Hastelloy C-4 is easily weldable, and it resists grain boundary precipitation during welding.
Main industries include chemical processing, pollution control, pharmaceuticals, and power generation.
It can be used safely up to 1040 °C without losing corrosion resistance.
Yes, we provide tailored solutions including custom machining, cutting, and processing based on project requirements.
15. Conclusion
Hastelloy C-4 is a high-performance nickel chromium molybdenum alloy engineered for extreme corrosion resistance and high-temperature stability. Its unique combination of properties makes it a trusted choice for chemical processing, pollution control, power generation, and marine engineering.
At Huaxiao-Alloy, we deliver Hastelloy C-4 products with unmatched quality assurance, global reach, and technical expertise. Whether you require tubes, plates, fittings, or custom-machined parts, we are committed to being your reliable partner.
📩 Contact us now at [email protected] or 📱 WhatsApp +1 (579) 300-2733 for a detailed quotation.
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