Stainless pipe fitting,stainless fitting,duplex stainless,31803,32750,32760,we are one of largest sour service stainless fitting supplier according to ISO 10156.
When your process demands a material that handles everything from cryogenic temperatures to 1095°C (2000°F) without cracking or corroding, Alloy 600 (UNS N06600) delivers. This solid-solution strengthened nickel-chromium austenitic alloy solves the stress corrosion cracking issues that plague 300-series stainless steels, making it one of the most widely trusted materials across nuclear, petrochemical, thermal power, industrial furnace, and offshore industries worldwide.
1. What Makes Alloy 600 Different
Alloy 600 fully complies with ASTM B166, ASTM B167, ASTM B409, and ASME SB-166/SB-167 specifications. Its high-nickel, chromium-balanced chemistry naturally forms a dense, self-repairing passive oxide layer on the surface. As a result, the alloy provides:
- Outstanding high-temperature oxidation and scaling resistance
- Excellent carburization and chloride pitting resistance
- Reliable protection against alkaline caustic corrosion
- Complete immunity to chloride stress corrosion cracking (SCC)
Unlike ordinary stainless steel, Alloy 600 keeps its mechanical integrity and corrosion resistance stable in high-temperature steam, high-pressure brine, and strong alkaline environments. This reliability makes it a universal, high-performance nickel alloy for extreme industrial service.
2. Chemical Composition (wt%) – The Foundation of Reliability
The composition strictly follows UNS N06600 registered standards, ensuring consistent corrosion resistance, high-temperature stability, and mechanical performance.
| Element | Ni (min) | Cr | Fe | C (max) | Mn (max) | Si (max) | Cu (max) | P (max) | S (max) |
|---|---|---|---|---|---|---|---|---|---|
| Specification | 72.00 | 14.00 – 17.00 | 6.00 – 10.00 | 0.15 | 1.00 | 0.50 | 0.50 | 0.030 | 0.015 |
Why this composition matters:
- The ultra-high nickel matrix fundamentally resists chloride and caustic-induced SCC.
- Chromium ensures excellent high-temperature oxidation resistance and anti-scaling capability.
- A balanced iron content optimizes hot workability and structural toughness, enabling the alloy to perform reliably under both corrosive media and long-term high-temperature cycling.
3. Heat Treatment and Mechanical Properties
3.1 Heat Treatment Process
We supply all Alloy 600 products in full solution-annealed condition. The standard treatment runs at 1010°C – 1095°C with rapid air cooling or water quenching. This process fully dissolves intermetallic precipitates, homogenizes the austenitic microstructure, eliminates residual cold work stress, and maximizes ductility, formability, and high-temperature creep resistance. Every production batch comes with complete heat treatment records, PMI spectral reports, and mechanical test certificates.
3.2 Room-Temperature Mechanical Properties (Annealed)
- Tensile Strength: ≥ 550 MPa
- Yield Strength (0.2% Offset): ≥ 240 MPa
- Elongation: ≥ 30%
- Brinell Hardness: ≤ 200 HB
3.3 Physical and High-Temperature Characteristics
- Density: 8.47 g/cm³
- Mean Linear Expansion Coefficient (20–1000°C): 15.8 × 10⁻⁶ /°C
- Maximum Continuous Service Temperature (oxidizing atmosphere): up to 1095°C
- Thermal Cycling Behavior: Excellent structural stability, stable creep rupture strength, and minimal thermal deformation under long-term high-temperature operation.
4. Core Performance Advantages
4.1 Complete SCC Immunity
Thanks to the high-purity nickel-based microstructure, Alloy 600 completely avoids chloride stress corrosion cracking. It stays stable in high-temperature, high-pressure water, steam, brine, and strong alkaline media — an irreplaceable feature for nuclear energy and high-pressure chemical equipment.
4.2 Superior High-Temperature Oxidation and Carburization Resistance
The chromium-rich passive film provides durable anti-oxidation and anti-scaling performance. Alloy 600 effectively resists carburization and nitriding penetration in furnace atmospheres, making it ideal for radiant tubes, furnace rollers, and heat treatment fixtures that run continuously at high temperatures.
4.3 Broad Multi-Medium Corrosion Resistance
The alloy handles alkaline solutions, seawater, atmospheric corrosion, organic acids, and mild acidic media with ease. It delivers far more reliable performance than ordinary stainless steels in complex chemical and marine service environments.
4.4 Excellent Fabricability and Weldability
In the solution-annealed condition, Alloy 600 offers superior hot forging, cold bending, and precision machining performance. You can weld it using GTAW, GMAW, and SMAW processes with matched nickel-based consumables, benefiting from low cracking sensitivity and stable forming quality for on-site piping and equipment fabrication.
4.5 Stable Cryogenic Toughness
Alloy 600 undergoes no ductile-to-brittle transition at ultra-low temperatures. It retains excellent impact toughness and structural integrity, so it also suits cryogenic storage and low-temperature industrial equipment.
5. Product Range and Specifications
We supply a full range of ASTM B166/B167 standard Alloy 600 (UNS N06600) industrial products, covering finished fittings and raw materials for high-temperature and anti-corrosion projects.
- Forged Pipe Fittings: Seamless elbows, equal/reducing tees, concentric/eccentric reducers, pipe caps. Size range: NPS 1/2 – NPS 48, wall thicknesses SCH10 – SCH160, with custom heavy-wall options.
- Seamless Pipes and Tubes: Hot-finished and cold-drawn, outer diameters 16 mm – 720 mm, wall thicknesses 3 mm – 90 mm. Custom fixed-length cutting available.
- Plates, Sheets, and Bars: Thick plates, thin sheets, round bars, and flat bars. We also support custom forging blanks and precision machining.
- High-Pressure Flanges and Custom Forgings: WN, SO, blind flanges, and special-shaped pressure-bearing forgings.
6. Main Application Fields
- Nuclear Power: Steam generator tubing, reactor internals, high-pressure pipeline fittings, nuclear waste treatment components
- Petrochemical and Chemical: Caustic evaporation equipment, high-pressure reactor piping, heat exchanger tubes, acid-base process fittings
- Industrial Heat Treatment Furnaces: Radiant tubes, furnace rollers, carburizing fixtures, high-temperature muffles, continuous furnace parts
- Thermal Power and Energy: Boiler superheater components, high-temperature flue gas pipelines, steam header fittings, waste heat recovery parts
- Offshore and Marine: Seawater corrosion-resistant pipeline accessories, desalination equipment parts, offshore platform structural fittings
7. Quality Control and Product Marking
All Alloy 600 UNS N06600 products are manufactured under our ISO 9001 quality management system. We follow a standardized quality control procedure: raw material spectral re-inspection → hot forming and solution heat treatment → mechanical property testing → NDT flaw detection → dimensional inspection → laser marking and sealed packaging.
Finished products are free from surface cracks, inclusions, laps, and oxidation defects. Standard laser marking includes brand information, grade (Alloy 600 / UNS N06600), ASTM standard, heat batch number, dimensions, and wall thickness — fully compliant with international industrial procurement and third-party inspection requirements. Every shipment comes with EN 10204 3.1 mill certification.
Related resources: Browse our full range of nickel alloy pipe fittings & seamless tubes, or learn more about our manufacturing capabilities on the C&N YouTube channel for product testing and factory updates.
