Gh3625 vs Gh4169 Nickel-Based Alloy Aerospace Plate
Gh3625 vs Gh4169 Nickel-Based Alloy Aerospace Plate
GH4169 (Inconel 718) and GH3625 (Inconel 625) are premium nickel-based aerospace alloys for high-temperature, high-strength sheet metal. GH4169 is a precipitation-hardening alloy (up to 650°C), providing engines with superior strength, fatigue resistance, and creep resistance; while GH3625 is a solid-solution-strengthened alloy optimized for temperatures up to 1000°C and offers excellent corrosion resistance and weldability.
What is the composition of GH4169 alloy?
The chemical composition of GH4169 alloy is as follows: Ni 53.44%, Cr 18.56%, Mo 3.02%, Nb 5.3%, Al 0.44%, Ti 1.04%, C 0.026%, P 0.005%, S 0.001%, B 0.002%, Fe balance (weight percentage).
1. Comparison of chemical composition of GH3625 and GH4169 plates (wt%)
| Element | GH3625 (Inconel 625) | GH4169 (Inconel 718) | Key Difference |
|---|---|---|---|
| Nickel (Ni) | 58.0 min (Balance) | 50.0 – 55.0 | GH3625 has higher Ni |
| Chromium (Cr) | 20.0 – 23.0 | 17.0 – 21.0 | GH3625 higher Cr |
| Iron (Fe) | ≤ 5.0 | Balance (~18-20) | GH4169 has much higher Fe |
| Molybdenum (Mo) | 8.0 – 10.0 | 2.80 – 3.30 | GH3625 has ~3x more Mo |
| Niobium (Nb) | 3.15 – 4.15 | 4.75 – 5.50 | GH4169 higher Nb |
| Titanium (Ti) | ≤ 0.40 | 0.65 – 1.15 | GH4169 higher |
| Aluminum (Al) | ≤ 0.40 | 0.20 – 0.80 | GH4169 higher |
| Carbon (C) | ≤ 0.10 | ≤ 0.08 | Similar |
| Manganese (Mn) | ≤ 0.50 | ≤ 0.35 | Similar |
| Silicon (Si) | ≤ 0.50 | ≤ 0.35 | Similar |
| Phosphorus (P) | ≤ 0.015 | ≤ 0.015 | Similar |
| Sulfur (S) | ≤ 0.015 | ≤ 0.015 | Similar |
| Boron (B) | – | 0.002 – 0.006 | GH4169 unique |
| Cobalt (Co) | ≤ 1.0 | ≤ 1.00 | Similar |
Click to download the GH4169 alloy PDF file now
2. Comparison of room temperature mechanical properties of Gh3625 and Gh4169 sheets
| Property | GH3625 (625) (Annealed) | GH4169 (718) (Aged) | Advantage |
|---|---|---|---|
| Tensile Strength, Ultimate (MPa) | ≥ 830 (120 ksi) | ≥ 1275 (185 ksi) | GH4169 (~54% higher) |
| Tensile Strength, Yield (MPa) | ≥ 415 (60 ksi) | ≥ 1035 (150 ksi) | GH4169 (~150% higher) |
| Elongation at Break (%) | ≥ 30 | ≥ 12 | GH3625 (more ductile) |
| Reduction of Area (%) | ≥ 40 | ≥ 15 | GH3625 |
| Hardness | ~22 HRC (96 HRB) | 35 – 40 HRC | GH4169 harder |
| Modulus of Elasticity (GPa) | ~207 | ~200 | Similar |
| Poisson's Ratio | 0.29 – 0.30 | 0.29 – 0.30 | Similar |
| Density (g/cm³) | 8.44 | 8.19 | GH4169 lighter |
Applications of Gh3625 and Gh4169 sheet metal properties
GH3625 (Alloy 625)
GH3625 (UNS N06625) is a solid solution strengthened alloy that requires no aging treatment. Its superior performance stems from its high molybdenum (9%) and chromium content.
Key Advantages: Virtually unaffected by chloride stress corrosion cracking (SCC) and pitting corrosion in seawater.
Optimal Applications: Seawater systems, flue gas desulfurization (FGD), pharmaceutical reactors, and offshore manifolds.
Commercial Advantages: The most cost-effective solution for providing long-term corrosion protection in acidic environments.
GH4169 (Alloy 718)
GH4169 (UNS N07718) is a precipitation hardening alloy that utilizes niobium (Nb) to achieve exceptional strength.
Key Advantages: Excellent high-cycle fatigue strength and creep rupture strength, up to 700°C.
Optimal Applications: Rotating rings, high-pressure fuel lines, turbine disks, and engine structural components.
Commercial significance: A necessary investment to ensure flight safety and the integrity of high-voltage structures.
5. Performance Comparison Table of GH4169 and GH3625
| Technical Feature | GH3625 (Alloy 625) | GH4169 (Alloy 718) | Industrial Impact |
| Strengthening Method | Solid Solution (Mo, Nb) | Precipitation Hardening (γ′′) | GH4169 is much "stiffer." |
| PREN Value (Pitting) | ≥ 45 - 52 (Superior) | ~ 30 - 31 | GH3625 is the Pitting King. |
| Yield Strength (650°C) | ~ 300 - 350 MPa | ≥ 850 MPa | GH4169 is 2.5x Stronger. |
| Fatigue Life | Moderate | Elite (Designed for HCF) | GH4169 for rotating parts. |
| Acid Resistance | Ultimate (H2SO4, HCl) | Moderate (Oxidation only) | GH3625 for Chemicals. |
| Weldability | Superior (No Aging req.) | Excellent (Delayed Aging) | GH3625 is easier for field ops. |
6. GH4169 and GH3625 Application Matrix
| Component Type | Recommended Grade | Commercial Justification |
| Seawater Valves/Piping | GH3625 / 625 | Superior Industrial Durability in brine. |
| Rotating Turbine Rings | GH4169 / 718 | High fatigue resistance prevents fracture. |
| Sour Gas (H2S) Internals | GH3625 / 625 | Highest resistance to sulfide cracking. |
| High-Pressure Fasteners | GH4169 / 718 | Elite yield strength prevents loosening. |
Why Choose Gnee Alloy?
As a professional Tier-1 manufacturer, Gnee Alloy offers more than just raw material sheets:
✅️VIM + VAR Melting: Ensures ultrapure chemical composition for both grades, maximizing part life.
✅️AS9100 Certification: Fully compliant with aerospace and energy management standards.
✅️Full Traceability: Each sheet comes with an EN 10204 3.1 MTC certificate, recording PREN values and high-temperature mechanical properties.
✅️Wholesale Pricing: Highly competitive pricing for bulk purchases and regular MRO projects.
Gnee Steel GH4169(inconel 718) Certificate
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Steel GH4169 Product Packing
Contact us for the latest export price quote for GH4169 Alloy
FAQ
Q1: Can GH4169 be used in seawater if I coat it?
A: Coating helps, but for mission-critical parts exposed to flowing seawater, GH3625 is much safer. Coatings can chip, but GH3625's corrosion resistance is inherent in its chemistry.
Q2: Which alloy is easier for custom fabrication?
A: GH3625. It is more ductile and doesn't require the complex 16-hour double-aging heat treatment that GH4169 needs to reach its performance specs. This reduces your secondary labor costs.
Q3: Is GH4169 equivalent to Inconel 718 in price?
A: Generally, GH4169 is more expensive due to the higher Niobium content and the multi-stage vacuum melting and heat treatment cycles required for aerospace-grade quality.
Q4: Do you offer cut-to-size services for energy projects?
A: Yes. We offer precision laser and waterjet Cut-to-Size blanks for both grades to minimize your material waste.
