GH3128 Nickel Alloy (GH128): The Solid Solution Superalloy for 950°C Service

1. GH3128 Nickel Alloy (GH128)

GH3128 is a solid solution strengthened nickel-based superalloy for continuous service up to 950°C, with short-term tolerance to 1000°C. It combines high chromium (≈20%) for oxidation resistance with tungsten and molybdenum (≈8% each) for strength. Small additions of boron, cerium and zirconium stabilize grain boundaries during long-term thermal exposure. The alloy is widely used in aerospace combustion systems, industrial furnaces, and gas turbine hot sections.

2. Key Features of GH3128

1. Achieves high-temperature strength through solid solution strengthening — no precipitation hardening required.
2. Resists oxidation and hot corrosion via a dense, adherent chromium oxide scale.
3. Tungsten and molybdenum improve resistance to carburization and sulfidation.
4. Cobalt enhances thermal fatigue resistance and microstructural stability.
5. Good ductility, stamping performance, and deep drawability for complex thin-sheet parts.
6. Excellent weldability (GTAW and GMAW) for fabricated structures.
7. Available as sheet, plate, strip, bar, wire, tube, pipe, forgings, and filler metals.

3. GH3128 Chemical Composition (wt.%)

4. Physical and Mechanical Properties

5. High-Temperature Performance and Corrosion Resistance

• Oxidation: Chromium forms a protective oxide scale that stays intact during repeated thermal cycling, making the alloy ideal for flame tubes, transition ducts, and afterburner liners.
• Creep: Usable strength up to approximately 950°C under moderate stress. For heavily loaded rotating parts, consider precipitation-hardened alloys such as Alloy 718 or Waspaloy.
• Wet corrosion: In severe aqueous or reducing environments, Alloy 625 or C-276 provide better resistance.

6. Typical Applications

1. Gas turbine combustion chambers and transition ducts
2. Flame tubes and afterburner components
3. Industrial furnace fixtures, radiant tubes, and heat treatment baskets
4. High-temperature heat exchangers and exhaust manifolds
5. Springs, fasteners, and sealing rings in hot zones
6. Wire mesh and electrical resistance heating elements

7. Available Forms and Standards

8. Welding and Fabrication

1. Welding: GTAW for precision thin sheet; GMAW for production; SMAW only for repair or heavy sections.
2. Post-weld treatment: Stress relief or solution annealing may be applied based on service demands; full precipitation hardening is not needed.
3. Forming: Excellent stamping and deep drawing behavior for complex shapes.
4. Machining: Use rigid setups, sharp carbide tools, low cutting speeds, and ample coolant to manage work hardening.

9. Why Source GH3128 from Us?

1. Full chemical analysis and mechanical testing on every lot.
2. Ultrasonic testing (UT) and positive material identification (PMI).
3. Dimensional inspection and third-party certification (SGS, BV, TUV, DNV) available.
4. Global delivery of sheet, plate, bar, wire, tube, pipe, flanges, and custom forgings.
5. Technical support for aerospace, power generation, petrochemical, and industrial heating projects.

Contact us to discuss your high-temperature material requirements.