Inconel 625 Spring Manufacturer
Coiling Tech specializes in Inconel springs and manufactures Inconel 625 springs for many industries and applications that need Alloy 625's oxidation and corrosion-resistant properties, like seawater applications. Inconel 625 is a Nickel-Chromium-Molybdenum-Columbium (Niobium) alloy with excellent oxidation and corrosion resistance, with strength at high temperatures. Inconel has high strength properties as it contains molybdenum and columbium on the nickel-chromium matrix.
| Technical Specification | Inconel 625 |
|---|---|
| Nominal Composition |
Ni:58.0 min Mo: 8.0 - 10.0 Cb (Nb): 3.15 - 4.15 |
| Density |
0.305 lb./in3, (8.44 g/cm3) |
| Modulus of Elasticity (E) |
At 70°F (20°C):30.1 x 103 ksi |
| Modulus of Rigidity (G) |
At 70°F(20°C): 11.8 x103 ksi |
| Coefficient of Expansion |
7.4 µin/in.-°F (70°F to 600°F) 13.3 µm/m-°C (20°C to 300°C) |
| Electrical Resistivity |
50.8 µΩ.in, (129 µΩ.cm) |
| Thermal Conductivity |
68 Btu-in/ft2hr-°F, (12.0 W/m-K) |
| Min Size |
0.0025 in (0.064 mm) |
| Max Temp |
370oC (700oF) |
| Uses of Inconel 625 springs |
Inconel 625 is resistant to chloride-ion stress-corrosion cracking and pitting making it suitable for springs operated in seawater applications. |
Inconel 625 Springs FAQs
What makes Inconel 625 a preferred choice for seawater and marine spring applications?
Inconel 625 (UNS N06625) is a nickel-chromium-molybdenum-niobium alloy with outstanding resistance to chloride-ion stress corrosion cracking and pitting—the failure modes that cause most other alloys to fail in prolonged seawater exposure. Its combination of approximately 22% chromium and 9% molybdenum creates a passive film highly resistant to chloride attack across a wide pH and temperature range. Inconel 625 also resists crevice corrosion in seawater at elevated temperatures, a condition that can cause even 316 stainless steel to fail in subsea applications.
What is the maximum operating temperature for an Inconel 625 spring?
Inconel 625 springs maintain reliable strength and corrosion resistance for spring applications up to approximately 700°F (371°C) continuously, with corrosion resistance maintained to much higher temperatures in oxidizing environments. Above approximately 1,100°F (593°C), the alloy can sensitize through carbide precipitation at grain boundaries in certain environments, which should be evaluated against the specific service exposure before specification.
How does Inconel 625 compare to Inconel 718 for spring design?
Inconel 718 generally provides higher tensile and yield strength—particularly in the precipitation-hardened condition—and a wider high-temperature operating range up to 1,300°F (704°C), making it the stronger choice when maximum strength across a wide temperature range governs the design. Inconel 625 is primarily a solid-solution-strengthened alloy (not age-hardenable) and provides lower strength than aged 718, but its exceptional resistance to chloride-induced corrosion in seawater and subsea environments often makes it the first-choice specification when corrosion resistance rather than maximum strength is the primary design driver.
What is the smallest wire diameter available for Inconel 625 springs?
Coiling Technologies manufactures Inconel 625 springs down to 0.0025 inches (0.064 mm) in wire diameter—enabling precision instrumentation springs, oceanographic sensor springs, and fine-wire medical applications in addition to the standard industrial spring size range. This fine-wire capability in Inconel 625 is uncommon in the spring manufacturing industry and supports applications requiring both corrosion resistance and very fine wire geometry.
Is Inconel 625 a suitable substitute if my design currently specifies Inconel 600?
It can be, particularly if your application involves seawater, chloride-containing process fluids, or mixed-acid environments. Inconel 625 offers meaningfully better pitting and stress corrosion cracking resistance than Inconel 600 in chloride environments, and higher room-temperature strength due to solid-solution strengthening from its molybdenum and niobium content. Coiling Technologies' engineering team can review your specific operating conditions, current Inconel 600 specification, and service requirements to confirm whether upgrading to 625 is appropriate and cost-justified.
What industries most commonly specify Inconel 625 springs?
Inconel 625 springs are most common in: marine and subsea equipment (subsea tree actuators, ROV components, oceanographic instrument springs, subsea wellhead components), oil and gas processing (production equipment with chloride-containing fluids, topside marine equipment), chemical processing (aggressive acid and mixed-acid environments), deep sea research (oceanographic instruments, research submersibles), and aerospace applications where seawater or chloride exposure combined with moderate temperature eliminates stainless steel as a viable option.
