Engineering Knowledge Center

Choosing Inconel 625, 617 or 718

A practical guide to nickel-alloy selection for corrosion, elevated temperature and mechanical strength.

625

Strong corrosion resistance and weldability make 625 a common choice for corrosion-resistant weld overlays and oil & gas / chemical service.

617

Designed around elevated-temperature strength plus oxidation/carburization resistance; a different design target from corrosion-overlay-focused 625.

718

A precipitation-hardenable high-strength alloy used where mechanical strength and fatigue are critical. It should not be treated as the default choice for corrosion overlay.

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