Inconel 617 (UNS N07617)

Inconel 617 (also specified as UNS N07617) is a solid-solution strengthened nickel-chromium-cobalt-molybdenum superalloy designed for extreme high-temperature service. It combines high strength, outstanding oxidation resistance and excellent resistance to a wide range of corrosive environments, retaining useful properties above 980 °C (1800 °F).

Overview

• Category: Solid-solution strengthened nickel-based superalloy (Ni-Cr-Co-Mo-Al-Ti)
• Key feature: High creep-rupture strength above 980 °C (1800 °F) for gas turbine and high-temperature process components
• Available forms: Round bar / rod, plate, sheet, pipe & tube, forgings, and custom profiles to order

Chemical Composition (wt%)

*Typical balance values; full composition ranges are supplied on the mill certificate (EN 10204 3.1).

Physical Properties

Mechanical Properties & High-Temperature Strength

Key Features

1. High-temperature performance: High strength and oxidation resistance up to about 1200 °C service temperature; a stable protective oxide scale forms at temperature, providing corrosion and oxidation protection. Strength is retained up to roughly 1150 °C (2100 °F).
2. Corrosion resistance: Highly resistant to reducing media and to both oxidising and reducing environments; also resists carburising atmospheres and aqueous media.
3. Metallurgical stability: Excellent resistance to embrittlement and microstructural degradation, even after long-term thermal exposure.

Machining & Forming

• Machining, welding and forming can be carried out using standard techniques for nickel-based alloys;
• Use sharp cutting tools with positive rake angles;
• Use sufficient feeds and depths of cut; cobalt-grade roughing tools are recommended, and tools should be inspected / replaced frequently as work hardening occurs.

Welding

• Filler / consumables: Inconel Welding Electrode 117 (covered electrode) and Inconel Filler Metal 617 (bare wire);
• Recommended processes: GTAW (TIG) and GMAW (MIG);
• Process parameters must be controlled carefully to avoid hot-cracking and loss of mechanical properties in the weld and heat-affected zone.

Heat Treatment

• Alloy 617 cannot be hardened by heat treatment; hardness levels are adjusted by cold working;
• Heat treatment (solution annealing) is used to optimise creep and stress-rupture properties. The key is to develop a sufficiently coarse grain size for creep resistance without sacrificing room-temperature strength.

Typical Applications

1. Power generation: superheater and reheater components in steam generators, nuclear and fossil-fired plant;
2. Aerospace & gas turbines: ducts, combustor cans and transition liners for aircraft gas turbines;
3. Petrochemical processing: high-temperature process equipment and piping;
4. Nitric-acid production: catalyst grid supports;
5. Molybdenum refining: heat-treatment baskets and reduction boats.

For detailed datasheets, mill certificates (EN 10204 3.1) or inquiries on specific sizes and tolerances, please contact our sales & engineering team.