For engineers in the aerospace and industrial heating sectors, the primary concern with GH4169 welded pipe is weld integrity. Under extreme thermal stress (up to 700°C), conventional welded pipe typically suffers from the following problems:
Hot cracking: Microcracks develop due to trace impurities in the weld area.
Grain coarsening: Reduced weld strength leads to premature fatigue failure.
Stress concentration: Improper heat treatment causes localized warping and failure.
At Gnee Steel, we eliminate these risks. As a Tier 1 supplier, our precision manufacturing processes ensure that the weld area maintains the same structural integrity and mechanical properties as the base material.
Check Our GH4169 Welded Pipe Sizes & Pricing
High-quality GH4169 precision welded nickel alloy tube
High-quality GH4169 precision welded nickel alloy tube
High-quality GH4169/N07718 precision-welded nickel alloy tubing is premium high-temperature and corrosion-resistant piping designed for the harsh environments of the aerospace, energy, and petrochemical industries. These tubings exhibit exceptional tensile strength, creep strength, and fracture strength (650°C to 1200°C) and are reinforced, welded, and heat-treated with niobium.
Is Inconel 718 a nickel-based superalloy?
Inconel 718 is a nickel-based superalloy, ideal for applications requiring high strength to be maintained over a temperature range from low temperatures to 1400°F (760°C).
1. GH4169 Pipe Technical Specifications
We specialize in large-diameter GH4169 steel pipes that most seamless steel pipe manufacturers cannot provide.
| Feature | Specification Details | Industrial Advantage |
| Outside Diameter (OD) | 150mm to 1200mm (6" to 48") | Perfect for heavy-duty exhaust ducting. |
| Wall Thickness (WT) | 2.0mm to 30.0mm | High-pressure rated structural support. |
| Standard Compliance | AMS 5596, ASTM B670, ASME SB670 | Certified Aerospace Grade quality. |
| Inspection (NDT) | 100% Radiographic (RT) / X-Ray | Guaranteed zero weld defects. |
| Surface Condition | Pickled, Polished, or Bright Annealed | Ready for immediate assembly. |
2. Chemical composition (weight percentage) of GH4169 welded pipe
| Element | GH4169 Welded Tube Content (%) | Standard Requirement | Notes |
|---|---|---|---|
| Nickel (Ni) | 50.0 – 55.0 | 50.0 – 55.0 | Matrix element; provides corrosion resistance and high-temperature stability |
| Chromium (Cr) | 17.0 – 21.0 | 17.0 – 21.0 | Provides oxidation and corrosion resistance |
| Iron (Fe) | Balance | Balance | Typically ~18-20% |
| Niobium (Nb) | 4.75 – 5.50 | 4.75 – 5.50 | Primary γ″ strengthening element |
| Molybdenum (Mo) | 2.80 – 3.30 | 2.80 – 3.30 | Solid-solution strengthening and pitting resistance |
| Titanium (Ti) | 0.65 – 1.15 | 0.65 – 1.15 | Forms γ′ strengthening phase with Al |
| Aluminum (Al) | 0.20 – 0.80 | 0.20 – 0.80 | Forms γ′ strengthening phase with Ti |
| Cobalt (Co) | ≤ 1.00 | ≤ 1.00 | Residual element |
| Carbon (C) | ≤ 0.08 | ≤ 0.08 | Low carbon for weldability |
| Manganese (Mn) | ≤ 0.35 | ≤ 0.35 | Deoxidizer |
| Silicon (Si) | ≤ 0.35 | ≤ 0.35 | Deoxidizer |
| Phosphorus (P) | ≤ 0.015 | ≤ 0.015 | Low for good toughness |
| Sulfur (S) | ≤ 0.015 | ≤ 0.015 | Low for hot workability |
| Boron (B) | ≤ 0.006 | ≤ 0.006 | Grain boundary strengthener |
| Copper (Cu) | ≤ 0.30 | ≤ 0.30 | Residual element |
| Tantalum (Ta) | ≤ 0.05 | ≤ 0.05 | Residual element |
Click to download the GH4169 alloy PDF file now
3. Physical properties of GH4169 welded pipe
| Property | Value |
|---|---|
| Density | 8.19 g/cm³ |
| Melting Range | 1260 – 1336°C |
| Thermal Conductivity (20°C) | 11.4 W/m·K |
| Thermal Conductivity (500°C) | ~16.0 W/m·K |
| Coefficient of Thermal Expansion (20-100°C) | 13.0 × 10⁻⁶/°C |
| Coefficient of Thermal Expansion (20-500°C) | ~14.5 × 10⁻⁶/°C |
| Coefficient of Thermal Expansion (20-700°C) | ~15.5 × 10⁻⁶/°C |
| Specific Heat (20°C) | 435 J/kg·K |
| Electrical Resistivity (20°C) | 1.25 µΩ·m |
| Magnetic Properties | Slightly magnetic (due to Fe content) |
4. GH4169 welded pipe dimensions
GH4169 welded pipe size range:
| Parameter | Typical Range |
|---|---|
| Outside Diameter (OD) | 6 mm – 300 mm (0.25" – 12") |
| Wall Thickness | 0.5 mm – 12 mm (0.020" – 0.500") |
| Length | Up to 15,000 mm (custom available) |
GH4169 welded pipe tolerances:
| Parameter | Tolerance |
|---|---|
| OD Tolerance | ±0.05 – ±0.25 mm (depending on diameter) |
| Wall Thickness Tolerance | ±10% – ±15% |
| Straightness | ≤ 1.5 mm/m |
5. GH4169 Welded Pipe: VIM + VAR High-Purity Raw Materials
The quality of high-quality welded pipe depends on the quality of the sheet metal used. Our base material is produced using a vacuum induction melting (VIM) + vacuum arc remelting (VAR) process.
Zero Inclusions: Ultra-low sulfur and phosphorus content (≤0.010%) prevents hot cracking during the liquid-solid phase transformation in the welding process.
Uniformity: Ensures uniform reaction throughout the pipe, from the weld to the pipe wall, during the final aging heat treatment.
vacuum induction melting (VIM) + vacuum arc remelting (VAR) process
6. Gnee Steel GH4169 Advanced Welding Technology
We utilize state-of-the-art automated TIG (Tungsten Inert Gas) and plasma arc welding systems to deliver superior weld surfaces.
Complete Penetration: Ensures no root defects or lack of fusion.
Matching Welding Wire: We use high-purity ERNiCr-3 or dedicated GH4169 welding wire to perfectly match the chemical composition of the base metal.
Controlled Shielding Gas: Double-sided argon protection prevents oxidation of both inner and outer surfaces.
7. GH4169 pipe quality assurance
As a Reliable Supplier, we provide peace of mind through a rigorous inspection protocol:
✅️100% X-Ray Inspection: Every inch of the weld seam is Radiographically Tested (RT) to ensure zero porosity or slag.
✅️Hydrostatic Testing: Verified integrity under high internal pressure.
✅️MTC 3.1 Certification: Full documentation of the chemical analysis and mechanical verification according to EN 10204.
✅️Third-Party Inspection: We welcome SGS, TUV, or BV audits to verify your project's specific requirements.
Gnee Steel GH4169 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 Pipe suppliers Packing
Contact us for the latest export price quote for GH4169 Alloy
FAQ
Q1: Can GH4169 welded pipe replace seamless pipe?
A: For large-diameter exhaust systems, structural rings, and low-to-medium pressure furnace ducting, our 100% RT-tested welded pipes are a Cost-effective Solution that offers the same high-temperature performance as seamless, often at a 30% lower cost.
Q2: How do you prevent the weld seam from being "softer" than the wall?
A: Through a specialized Double-Aging heat treatment after welding. This process precipitates the γ′′ phases uniformly across the weld zone, matching the hardness and strength of the parent plate.
Q3: What is the maximum length available for large pipes?
A: We provide standard 6-meter lengths, but our Custom Fabrication shop can provide sections up to 12 meters with specialized girth welding and inspection.
Q4: Do you offer bulk discounts for petrochemical projects?
A: Absolutely. As a direct factory, we offer tiered Wholesale Pricing and dedicated logistics support for large-scale energy infrastructure projects.
