Views: 41 Author: Wang Publish Time: 2024-07-09 Origin: Site
Hastelloy C4 is a nickel alloy with outstanding high-temperature stability, high ductility and corrosion resistance. Hastelloy C4 alloy can be forged, hot-upset and impact extruded. Although the alloy tends to work-harden, it can be successfully deep-drawn, spun, press formed or punched. And, C4 alloy is solution heat-treated at 1950ºF (1066ºC) and rapidly quenched.
Like other nickel alloys, Hastelloy C4 is ductile, easy to form and weld, and exceptionally resistant to stress. Also, C4 can withstand both oxidizing and non-oxidizing acids and is resistant to pitting and crevice attacks.
This alloy tolerates high temperatures and has weld geometry that makes excessive heat buildup unavoidable. Resistance to general and localized corrosion and stress corrosion cracking is generally similar to Hastelloy C276.
Hastelloy C4 alloy is in the Hastelloy family, known for its excellent corrosion resistance and high-temperature stability. JN is a Hastelloy B2, B3, C22, C4, C276, C2000, X, and G30 alloy supplier and manufacturer; our Hastelloy alloys meet ASTM, ASME, DIN, BS, GOST, JIS, and GB standards. Products include plates, bars, forgings, pipe fittings, flanges, prefabricated pipes, etc.
Hastelloy C4 main chemical composition includes nickel, molybdenum, chromium, and a small amount of carbon, silicon, iron and tungsten.
Among them, nickel as a basic composition, gives the C4 alloy good toughness and high-temperature strength;
Molybdenum and chromium improve the corrosion resistance of the alloy, especially in reducing and oxidizing media;
C4 alloy differs from other Hastelloys by having lower C, Si, Fe, and W. These compositional differences cause high-temperature stability.
Hastelloy C4 alloy is an austenite structure, which can maintain excellent mechanical properties and corrosion resistance at high temperatures. In addition, the alloy reduces the defects at the grain boundaries, improving the overall performance.
The Hastelloy C4 chemical composition is in the following table:
Composition | Value (%) |
Chromium, Cr | 14-18 |
Molybdenum, Mo | 14-17 |
Iron, Fe | 3 max |
Cobalt, Co | 2 max |
Manganese, Mn | 1 max |
Titanium, Ti | 0.7 max |
Silicon, Si | 0.08 max |
Phosphorus, P | 0.04 max |
Sulfur, S | 0.03 max |
Carbon, C | 0.015 max |
Nickel, Ni | Remainder |
Hastelloy C4 has outstanding high-temperature stability, excellent resistance to aggressive aqueous environments and good weldability. C4 is seen as more stable and better weldable than Alloy C276. Hastelloy C4 displays good ductility and corrosion resistance after long-time aging at 650 to 1040°C.
Hastelloy C4 has exceptional resistance to a variety of chemical process environments, including hot contaminated mineral acids, solvents, chlorine, and chlorine-contaminated media.
Alloy C276 and Alloy C4 perform similarly in many corrosive environments. However, in strong reducing media like hydrochloric acid, C276 is better. In highly oxidizing media, C4 outperforms C276. Alloy C4 offers good corrosion resistance to a wide variety of media, including organic acids and acid chloride solutions.
Forging: Hastelloy C4 can be processed by hot forging and cold forging. The temperature range of hot forging is 1150-950℃, and the temperature range of cold forging is 760-870℃.
Heat treatment: Hastelloy C4 can be heat treated by solution treatment and aging treatment. The solid solution treatment temperature is 1150-900℃ and the aging treatment temperature is 760℃. Hastelloy C4 requires careful heat treatment to achieve optimal mechanical properties.
The alloy is annealed at 1025°C-1125°C, followed by rapid cooling through water or air quenching. The material is then age-hardened by heating to 870°C-980°C for one hour, followed by water or air quenching.
Cold working: Hastelloy C4 has strong tensile and yield strength. This makes it good for cold working, like cold rolling and cold drawing.
Corrosion resistance: Hastelloy C4 has excellent corrosion resistance in acids, alkalis, salts and other media; especially in chlorine-containing media. Hastelloy C4 is a highly corrosion-resistant material, standing up well to several corrosive environments, including oxidizing and reducing acid environments. It has superior resistance to pitting, crevice corrosion, and stress cracking. In addition to its resistance to acid and highly corrosive environments, Hastelloy C4 also resists intergranular cracking in welding.
Mechanical properties: Hastelloy C4 has a high yield strength and tensile strength. Hastelloy C4 is classified as a difficult-to-machine alloy due to its high elasticity modulus and work hardening.
Therefore, special care must be taken when machining Hastelloy C4. Carbide-cutting tools are recommended to minimize tool wear and prolong tool life. High-speed steel tools are not recommended since they wear quickly.
Performance: Hastelloy C4's main advantage is its excellent corrosion resistance and resistance to thermal oxidation, but also has good mechanical properties and processability.
Welding: Hastelloy Welding material grades for Hastelloy C4 include ERNiCrMo-7 and ENiMo-7. Careful attention needs to be given when welding Hastelloy C4. The alloy can be readily welded, but the filler material selection is crucial to obtain optimal mechanical properties.
TIG welding is the most common method due to its low-heat input, allowing for successful welding without cracking. Moreover, post-welding heat treatment is required for Hastelloy C4 to reduce residual welding stress and restore mechanical properties.
Hastelloy C4 has become a top choice due to its mechanical and physical properties, exceptional corrosion resistance, and versatility. Whether in the chemical processing, aerospace, or pharmaceutical industry, Hastelloy C4 offers excellent corrosion resistance.
Hastelloy C4 is used in various industries, including chemical processing, aerospace, power generation, petrochemical, pharmaceuticals, and marine applications. This alloy suits sulfuric acid, hydrochloric acid, and acetic acid applications. It is commonly used in chemical reactors, heat exchangers, furnace components, and catalyst support grids.
Hastelloy C4 (UNS N06455) "equivalents" requires matching its specific composition, properties, and certifications.
| Standard | Equivalent Grades | Designation |
| UNS | N06455 | UNS N06455 |
| EN | NiCr16Mo16Ti | 2.4610 / NiMo16Cr16Ti |
| ISO | NiCr16Mo16 | ISO 6207: NiCr16Mo16 |
| GOST | ХН65М16ВТБ (KhN65M16VTB) | GOST 5632-2019 |
| JIS | NW 6415 | NW 6415 |
Hastelloy C4 (UNS N06455) has no universal identical substitute, but NiCr16Mo16Ti (2.4610) is its direct EN counterpart. For functional replacement:
Use C22 for severe oxidizing acids.
Choose C276 for broader acid mixes if post-weld heat treatment is feasible.
Chemical Composition:
C4 has a higher nickel content and lower iron content than C276. Its main feature is ultra-low contents of carbon and silicon.
C276 has lower nickel but contains tungsten, which C4 lacks. It also has slightly higher iron and silicon. Chromium and molybdenum compositions are very similar in both alloys.
Resistance to Different Corrosion Types:
C4 excels in reducing acid environments, particularly hot hydrochloric acid. Its low carbon/silicon makes it resistant to chloride stress corrosion cracking and gives it superior stability.
C276 offers broader overall corrosion resistance. It performs better than C-4 in oxidizing acids and is significantly more resistant to pitting.
Welding and Thermal Stability:
C4 is specifically designed for as-welded stability. Its low carbon/silicon minimizes harmful carbide precipitation in the heat-affected zone. This is crucial for parts undergoing repeated heating and cooling cycles without needing post-weld heat treatment.
C276 generally requires solution annealing after welding. Without this, the heat-affected zone can become more prone to attack, especially in highly corrosive conditions.
Performance at High Temperatures:
C4 is best suited for service temperatures up to about 400°C. Its strength drops faster above this point.
C276 retains its strength at significantly higher temperatures, largely due to its tungsten content. Hastelloy C276 is preferable for high-heat applications.
Typical Applications:
Use C4: The application involves hot reducing acids, like chemical reactors, heater tubes, and pipes for HCl service.
Use C276: The application involves mixed acids, oxidizing conditions, high chloride levels, or higher temperatures. It's for flue gas desulfurization systems, waste treatment, pulp & bleach plants, and seawater heat exchangers.
JN is a Chinese manufacturer and distributor of Hastelloy C4 products. We offer round bars, plates, tubes, pipe fittings, forgings,and flanges. Our service is one-stop, and we provide high-quality products at good prices.
Export to 40+ countries, internationally certified Hastelloy supplier. Welcome to learn more about nickel alloys.
