ASTM A790 UNS S31803 Seamless Pipes Exported To South Korea
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GNEE Stainless Steel has successfully completed another export project involving ASTM A790 UNS S31803 Seamless Pipes for a leading industrial equipment manufacturer in South Korea. The order was placed for a critical process pipeline system used in corrosive chemical media, where long-term reliability, pressure resistance, and corrosion performance were the customer's primary concerns.
South Korea remains one of Asia's most demanding industrial markets, particularly for petrochemical plants, LNG terminals, offshore engineering, desalination facilities, and heat exchanger manufacturing. Customers require not only compliance with ASTM A790 specifications but also complete material traceability, dimensional accuracy, and third-party inspection documentation.
Customer Technical Requirements
During the technical evaluation stage, the Korean customer submitted detailed specifications and requested additional inspection procedures beyond the standard ASTM A790 requirements to ensure long-term service reliability.
Order Specification
| Item | Specification |
|---|---|
| Product | ASTM A790 UNS S31803 Seamless Pipe |
| Material Grade | UNS S31803 Duplex Stainless Steel |
| Standard | ASTM A790 / ASME SA790 |
| Manufacturing | Seamless Cold Drawn |
| Outside Diameter | 168.3 mm |
| Wall Thickness | 14.27 mm |
| Length | 6000 mm / Customized |
| Surface Finish | Pickled & Passivated |
| Heat Treatment | Solution Annealed (1040–1120°C) + Water Quenched |
| Inspection Certificate | EN 10204 3.1 MTC |
| Additional Tests | Ferrite Test, Intergranular Corrosion Test, Penetrant Testing (PT), PMI, Hydrostatic Test |
Following order confirmation, GNEE organized production using premium duplex stainless steel billets. Each pipe underwent hot piercing, cold drawing, solution annealing, straightening, pickling, passivation, and dimensional inspection under strict process control.
To maintain the required duplex phase balance, solution annealing was performed between 1040°C and 1120°C, followed immediately by rapid water quenching. This process minimizes harmful intermetallic phase precipitation while preserving the optimal balance of ferrite and austenite required for superior mechanical strength and corrosion resistance.
Dimensional tolerances, straightness, wall thickness, and surface finish were inspected at each manufacturing stage to ensure compliance with ASTM A790 and customer specifications.
ASTM A790 UNS S31803 Pipe Production Live Scene
Quality Control
One of the customer's primary concerns was maintaining the proper ferrite-austenite balance, which directly affects corrosion resistance and mechanical performance.
GNEE therefore conducted Ferrite Content Testing using calibrated ferrite measuring equipment in accordance with internationally recognized inspection procedures.
Ferrite Test Results
| Test Item | Requirement | Actual Result |
|---|---|---|
| Ferrite Content | 35–55% | 43.6–47.9% |
| Microstructure | Duplex | Qualified |
If you are analyzing a specific metallographic inspection report for 2205 steel, please provide the following information: the measured ferrite content percentage; whether the report mentions any precipitated phases or inclusions; and the manufacturing process the component underwent (e.g., welding or forging). I can assist you in evaluating whether the material meets industry standards for your specific application.
Intergranular Corrosion Test
Since the pipes are intended for continuous exposure to chloride-containing process fluids, the customer required Intergranular Corrosion Testing (IGC Test) after heat treatment.
Representative specimens were tested according to ASTM corrosion evaluation methods after solution annealing.
Inspection results confirmed:
No intergranular cracking
No grain boundary sensitization
Uniform metallographic structure
Excellent resistance to localized corrosion
These results demonstrate that harmful chromium carbide precipitation was effectively prevented during heat treatment, ensuring long-term corrosion performance in aggressive industrial environments.
Penetrant Testing (PT)
To eliminate the possibility of surface discontinuities before shipment, every finished pipe underwent Liquid Penetrant Testing (PT).
The inspection focused on identifying:
Surface cracks
Seam defects
Pinholes
Grinding marks
Surface porosity
Processing defects
Following developer inspection, all tested pipes showed no relevant linear indications or surface-breaking defects, fully satisfying customer acceptance criteria.
Additional Quality Inspections Before Shipment
Beyond the customer's requested tests, GNEE also completed a comprehensive quality inspection program.
Quality Inspection Checklist
✅ Chemical Composition Analysis
✅ Mechanical Property Testing
✅ Hydrostatic Pressure Test
✅ Eddy Current Testing
✅ Ultrasonic Testing (UT)
✅ Dimensional Inspection
✅ Surface Roughness Inspection
✅ EN 10204 3.1 Material Test Certificate
Our engineering team maintained continuous communication with the customer throughout production, sharing manufacturing progress, inspection photos, testing reports, and packing details to ensure complete transparency.
Complete inspection reports, heat number traceability records, and quality documentation were submitted to the customer prior to shipment, providing full transparency throughout the project.
Export Packaging for Safe Delivery to South Korea
After final inspection approval, all seamless pipes were carefully packaged for ocean transportation using export-grade materials.
The packaging included waterproof wrapping, plastic end caps, anti-rust protection, reinforced wooden cases, and clearly marked heat numbers to ensure product traceability upon arrival. This packaging system minimizes the risk of mechanical damage and corrosion during long-distance shipment.
If you have project requirements for 2205 stainless steel pipes, we welcome your orders. GNEE maintains a large inventory of popular products for you to choose from. These are available in both seamless and welded forms with various surface finishes; please contact our factory today for detailed chemical composition specifications and free samples. We offer competitive prices and excellent service.
