1. What are the typical applications of Inconel 625, 718, 825, and X-750 tubes and pipes?
Answer:
Inconel 625: Marine, chemical processing, aerospace, and pollution control; excellent corrosion and high-temperature resistance.
Inconel 718: Aerospace turbine components, nuclear reactors, high-temperature fasteners; exceptional creep and fatigue resistance.
Inconel 825: Chemical processing, acid handling, oil & gas; outstanding resistance to oxidizing and reducing environments.
Inconel X-750: Turbine blades, springs, high-temperature fasteners; maintains strength and creep resistance at elevated temperatures.
2. What temperature ranges can these alloys operate at?
Answer:
Inconel 625: Up to 982°C (1,800°F) for continuous service.
Inconel 718: Up to 700°C (1,292°F) for high-strength applications.
Inconel 825: Up to 870°C (1,600°F) for corrosion resistance in harsh chemical environments.
Inconel X-750: Up to 700°C (1,292°F) maintaining creep and stress-rupture properties.
3. How do mechanical properties differ among these alloys?
Answer:
Inconel 625: Tensile strength ~690–830 MPa, excellent fatigue and creep resistance.
Inconel 718: Tensile strength ~1,240 MPa, excellent creep, rupture, and fatigue resistance.
Inconel 825: Tensile strength ~515–690 MPa, high corrosion resistance and moderate strength.
Inconel X-750: Tensile strength ~1,100 MPa, excellent high-temperature creep and stress-rupture properties.
4. Are these small diameter tubes and welded pipes weldable and machinable?
Answer:
Alloy weldability:
Inconel 625 & 825: Excellent weldability with standard nickel-alloy welding methods.
Inconel 718 & X-750: Weldable but require specialized techniques; post-weld heat treatment is often needed.
Machinability:
Inconel 625 & 825: Machinable with sharp tools and proper cooling.
Inconel 718 & X-750: Difficult to machine due to high strength and work hardening; slower cutting speeds recommended.
5. How should these tubes and pipes be stored and handled?
Answer:
Keep in a clean, dry storage area to prevent oxidation and contamination.
Avoid prolonged exposure to strong acids or chlorides unless the alloy is rated for it.
Handle carefully to prevent dents, scratches, or deformation, which could compromise fatigue or corrosion resistance.
Maintain original protective packaging until installation to preserve surface quality.
