Introduction

GH3128 (GH128) is a nickel-chromium-based solid-solution strengthened wrought superalloy designed for long-term service at temperatures up to 950°C (1742°F) The alloy is strengthened through tungsten (W) and molybdenum (Mo) additions—combined W+Mo content of approximately 16%—which significantly elevate the recrystallization temperature and creep resistance of the matrix Boron, cerium, and zirconium are added to purify and strengthen grain boundaries, further enhancing high-temperature durability The chemical composition is characterized by a nickel base (balance), 19–22% chromium for oxidation resistance, 7.5–9.0% tungsten, 7.5–9.0% molybdenum, 0.4–0.8% aluminum, and 0.4–0.8% titanium. This GH3128 alloy is defined by GB/T 14992 and is also available under the commercial designation GH128. While it has no direct UNS equivalent, some references associate it with UNS N06308 or Haynes 230 with compositional differences. This high temperature nickel alloy delivers high plasticity, excellent oxidation resistance, superior creep and rupture strength, and outstanding formability and weldability. It is the preferred material for aero-engine combustion chambers, afterburner casings, gas turbine components, industrial furnace equipment, and high-temperature structural parts. Available in a full range of product forms including GH3128 plate, sheet, bar, pipe, tube, wire, and forgings.

Chemical components（%）

Mechanical properties

Physical properties

GH3128 Superalloy Available Products and Standard

Grade: GH3128 / GH128

Type: Round Bar / Sheet / Plate / Strip / Wire / Seamless Tube / Forgings

Size Range:

• GH3128 Wire: 0.1 – 15.0 mm dia

• GH3128 Strip: 0.05 – 5.0 mm thick × 5 – 500 mm wide

• GH3128 Round Bar: 8 – 355 mm dia

• GH3128 Sheet / Plate: 0.5 – 180 mm thick

• GH3128 Seamless Tube: Custom sizes available

Surface: Annealed, Bright, Pickled, Ground

Testing: Chemical analysis, mechanical test (tensile strength, yield strength, elongation), hardness test, high-temperature stress rupture test, oxidation resistance test, stamping test, dimensional inspection

Applications

1. Aero-Engine Combustion Chambers & Afterburner Casings

• For combustion chamber flame tubes operating at temperatures up to 950°C, GH3128 plate and sheet deliver high-temperature strength and excellent oxidation resistance where conventional alloys would soften and deform.

• For afterburner casings and tailpipes in military and commercial jet engines, GH3128 superalloy provides superior creep resistance (900°C / 200 MPa: >200 hours endurance) and structural stability under extreme thermal cycling.

• For diffusers, stabilizers, and gas ducts in the hot section of turbine engines, GH3128 seamless pipe and tube maintain mechanical integrity at sustained elevated temperatures.

• For heat shields and thermal protection systems, GH3128 sheet offers excellent formability for complex thin-walled configurations combined with outstanding oxidation resistance.

2. Gas Turbines & Power Generation

• For industrial gas turbine combustion chamber components and turbine outer rings, GH3128 bar and round bar withstand high-temperature gas erosion and mechanical stress in power generation applications.

• For power generation equipment requiring reliable performance in high-temperature oxidizing environments, GH3128 plate provides long-term structural stability with low oxidation rates (<0.1 mg/cm²·h at 900°C).

• For boiler components and high-temperature ducting in thermal power plants, GH3128 welded pipe offers good weldability with joint strength coefficients exceeding 90%, ensuring reliability in field-fabricated systems.

3. Industrial Furnaces & Petrochemical Equipment

• For furnace rollers, radiant tubes, and heating elements in industrial heat treatment furnaces, GH3128 tube delivers exceptional thermal stability and creep resistance in continuous high-temperature operation.

• For petrochemical reforming furnaces and high-temperature process equipment, GH3128 sheet and plate resist oxidation and maintain mechanical properties at elevated temperatures in aggressive process environments.

• For kiln components and thermal processing equipment requiring long-term durability above 900°C, GH3128 forgings provide the structural integrity needed for heavy-duty high-temperature service.

4. Aerospace Structural Components & Fasteners

• For aircraft structural components requiring strength at temperature extremes, GH3128 round bar offers high tensile strength (850 MPa at room temperature) combined with excellent fabricability.

• For high-temperature fasteners and bolting in engine and airframe applications, GH3128 bar maintains clamping force and structural integrity through thousands of thermal cycles from ambient to 950°C.

• For precision-machined aerospace components demanding dimensional stability at elevated temperatures, GH3128 forged bar combines superior creep resistance with excellent machinability.

5. Nuclear Equipment & Heat Exchangers

• For intermediate heat exchangers in high-temperature gas-cooled reactors, GH3128 pipe is a candidate material due to its high-temperature stability, oxidation resistance, and good weldability.

• For nuclear power plant heating tubes and thermal transfer equipment, GH3128 tube maintains structural integrity in demanding high-temperature, high-pressure environments.

FAQ – GH3128 Superalloy

Q: What is the maximum operating temperature for GH3128?

A: GH3128 is suitable for continuous service up to 950°C (1742°F). The alloy maintains high plasticity, excellent creep resistance, and good oxidation resistance at this temperature. At 900°C, the alloy exhibits a tensile strength of 280 MPa and yield strength of 180 MPa.

Q: What is the difference between GH3128 and GH3044/GH3536?

A: GH3128 offers superior comprehensive performance compared to GH3044 and GH3536, with higher long-term endurance, better creep strength, and improved oxidation resistance. Its higher tungsten and molybdenum content (combined ~16%) provides elevated recrystallization temperature and superior creep resistance, making it the preferred choice for demanding high-temperature applications.

Q: Can GH3128 be welded, and what welding methods are recommended?

A: Yes. GH3128 offers excellent weldability with argon arc welding (TIG), spot welding, and seam welding. The alloy can also be joined by brazing. Welding can be performed with matching filler material (ERNiCrMo‑1 recommended), and the weld joint strength coefficient exceeds 90%, ensuring reliability in critical high-temperature applications.

We are a trusted GH3128 Supplier and GH3128 Manufacturer, China‑based, serving aerospace manufacturers, gas turbine builders, industrial furnace fabricators, and power generation equipment suppliers worldwide. All products comply with GB/T 14992 / GB/T 14995 with full mill test certificates, PMI verification, and dimensional inspection reports. We offer GH3128 plate, sheet, bar, round bar, pipe, tube, wire, welding wire, forgings, flanges, and fasteners in custom sizes, with cut‑to‑length, precision machining, and solution annealing services. Hot rolled, cold rolled, bright drawn, and precision ground options available. Contact us at info@monokj.com for size chart, pricing, or custom requirements.