Inconel 625® is a corrosion-resistant nickel-based superalloy widely recognized for its outstanding mechanical strength, thermal stability, and oxidation resistance. Its ability to perform reliably in highly corrosive and high-temperature environments makes it a preferred material across aerospace, marine, chemical processing, and energy industries.
Material Overview
Composed primarily of nickel (≈61%), chromium (≈22%), molybdenum (≈9%), and iron (≈5%), Inconel 625 gains its remarkable strength through solid-solution hardening and the precipitation of Nb-rich phases such as γ″ (Ni3Nb). The alloy maintains structural integrity at temperatures up to 982 °C and exhibits tensile strengths above 900 MPa (Gupta et al., 2015). Its microstructure consists of a stable FCC γ-matrix with finely dispersed carbides and intergranular Nb/Mo carbides (MC type) that enhance creep and fatigue resistance. Studies demonstrate that double-aging treatments at 732 °C and 621 °C accelerate γ″ precipitation, increasing strength while maintaining corrosion resistance (Rivolta et al., 2024). In high-temperature environments, Inconel 625 forms a continuous Cr2O3 protective layer that resists oxidation and carburization up to 1100 °C (Sharma & Sharma, 2021).
Applications and Advantages
Inconel 625 is utilized in turbine engines, chemical reactors, marine risers, and exhaust systems where both high strength and corrosion resistance are critical. Its exceptional resistance to pitting, crevice, and intergranular corrosion makes it ideal for seawater and acid-handling components. Fatigue studies reveal that Inconel 625 exhibits microvoid coalescence during fast fracture, with fatigue striations dominating crack propagation zones—demonstrating predictable and ductile failure modes under cyclic loading (Pereira et al., 2018). When exposed to elevated temperatures or aggressive chemical media, the alloy experiences minimal mass loss and structural degradation, even after prolonged thermal exposure (Sharma & Sharma, 2021). This combination of ductility, toughness, and environmental stability ensures exceptional service longevity in extreme operational environments.
Goodfellow Availability
Goodfellow supplies Inconel 625® in multiple forms including rods, sheets, and custom machined components, designed for use in high-temperature, high-corrosion applications. Each product meets stringent purity and microstructural standards, supporting research, prototyping, and industrial manufacturing.
Explore Inconel 625® – Corrosion Resistant Alloy Ni61/Cr22/Mo9/Fe5 and other advanced materials in Goodfellow’s online catalogue: Goodfellow product finder.
References
- Pereira, F. G. L., Lourenço, J. M., Nascimento, R. M., & Castro, N. A. (2018). Fracture behavior and fatigue performance of Inconel 625. Materials Research, 21(5), e20171089. https://doi.org/10.1590/1980-5373-MR-2017-1089
- Rivolta, B., Gerosa, R., & Panzeri, D. (2024). Influence of single- and double-aging treatments on the mechanical and corrosion resistance of Alloy 625. Superalloys, 14(7), 823. https://doi.org/10.3390/met14070823
- Gupta, R. K., Kumar, V. A., Gururaja, U. V., Shivaram, B. R. N. V., Prasad, Y. M., Ramkumar, P., Chakravarthi, K. V. A., & Sarkar, P. (2015). Processing and characterization of Inconel 625 nickel base superalloy. Materials Science Forum, 830–831, 38–42. https://doi.org/10.4028/WWW.SCIENTIFIC.NET/MSF.830-831.38
- Ferro, P., Fabrizi, A., Bonollo, F., & Berto, F. (2022). Influence of short-term post-welding heat treatments on corrosion resistance of UNS N06625 nickel–chromium–molybdenum alloy. Procedia Structural Integrity, 38, 121–128. https://doi.org/10.1016/j.prostr.2022.05.049
- Sharma, S. N., & Sharma, Y. C. (2021). Mass loss study at elevated temperature of Inconel 625 alloy in various mediums. Materials Today: Proceedings, 46, 1569–1574. https://doi.org/10.1016/j.matpr.2021.06.017