Hastelloy˘ C-4

HASTELLOY® C-4 alloy is a nickel-chromium-molybdenum alloy with excellent resistance to stress-corrosion cracking and to oxidizing atmospheres at high temperatures. It has virtually the same corrosion resistance as HASTELLOY®C-276 alloy. It exhibits exceptional resistance to a wide variety of chemical process environments.

 Chemical Composition Hastelloy˘ C-4

Applications of Hastelloy˘ C-4

Chemical processing equipment, nuclear fuel processing

Physical Properties

Hastelloy C4 Corrosion Resistance

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.

Hastelloy C4 Heat Treatment

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.

Hastelloy C4 Machining

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.

Hastelloy C4 Welding

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 of fusing Hastelloy C4 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.

Conclusion

Hastelloy C4 and Hastelloy C22 are excellent alloys for industrial applications, depending on the corrosive environment and temperature requirements of the medium. However, their properties differ in terms of chemical composition, temperature resistance, solderability, and price.

Hastelloy C4 has become a top choice among industries requiring high-performance alloys due to its unique mechanical and physical properties, exceptional corrosion resistance, and versatility. We have learned how Hastelloy C4 stands out in various applications, from its composition to its mechanical and physical properties. Whether operating in the chemical processing, aerospace, or pharmaceutical industry, Hastelloy C4 offers excellent corrosion resistance to help your equipment last longer and perform better.