Alloy 926 (UNS N08926), High-Chloride Resistant Super Austenitic Steel Round Bar

1. Material Overview

Alloy 926 ,also commonly known as 1.4529 (Incoloy 926) is a premium nitrogen-strengthened super austenitic nickel-iron-chromium-molybdenum alloy, manufactured in accordance with ASTM B625, B729, B775 and corresponding ASME SB industry specifications. Forgings, flanges & fittings: ASTM B564 / ASME SB564.

Developed as an upgraded version of Alloy 904L, UNS N08926 features optimized high molybdenum, nitrogen and nickel composition, achieving significantly improved local corrosion resistance and structural stability in harsh chloride-rich environments.

With a balanced multi-element alloy design, Alloy 926 forms a dense, stable passive film on the material surface, delivering outstanding resistance to pitting corrosion, crevice corrosion, stress corrosion cracking and uniform corrosion. The added nitrogen alloying significantly improves pitting and crevice corrosion resistance and enhances matrix strength without sacrificing ductility; the ultra-low carbon content reduces intergranular carbide precipitation risk and ensures good intergranular corrosion resistance. This alloy maintains stable performance in seawater, brine, flue gas desulfurization media, acidic solutions and high-chloride industrial wastewater, far outperforming conventional 316L and 904L stainless steels.

Widely supplied in seamless tubes, forged fittings, flanges, plates and custom industrial forgings, UNS N08926 has become the preferred super austenitic alloy for marine engineering, desalination, chemical processing and environmental protection equipment worldwide.

2. Incoloy 926 Chemical Composition (wt%)

The chemical composition strictly complies with UNS registered standards and international corrosion-resistant alloy and stainless steel standards, ensuring consistent corrosion resistance, mechanical stability and service reliability in extreme corrosive environments:

Note: High molybdenum content provides powerful resistance to pitting and crevice corrosion in chloride media. Nitrogen supplementation improves mechanical strength and inhibits intergranular corrosion, while high nickel content effectively prevents stress corrosion cracking. The ultra-low carbon formulation greatly reduces the risk of intergranular carbide precipitation after welding or thermal exposure, ensuring excellent intergranular corrosion resistance for long-term corrosive service.

3. Heat Treatment & Mechanical Properties

3.1 Heat Treatment Process

All Alloy 926 (UNS N08926) products are delivered in fully solution-annealed condition. Standard solution treatment is performed at 1100~1150℃ followed by rapid water quenching. This process fully dissolves precipitated carbides and intermetallic phases, homogenizes the austenitic microstructure, eliminates residual stress, and maximizes ductility, corrosion resistance and structural stability. Each production batch is supported by complete heat treatment records, PMI spectral reports and mechanical test certificates.

3.2 Room-Temperature Mechanical Properties (Annealed Condition)

• Tensile Strength: ≥650 MPa
• Yield Strength (0.2% Offset): ≥290 MPa
• Elongation: ≥35%
• Brinell Hardness: ≤220 HB

3.3 Physical & Service Characteristics

Density: 8.10 g/cm³; Average linear expansion coefficient (20~400℃): 15.3×10⁻⁶/℃. Alloy 926 features stable mechanical performance at room and medium temperatures, with excellent structural toughness and low deformation tendency. It maintains outstanding corrosion stability in high-salinity, acidic and oxidation environments, adapting to long-term continuous corrosive working conditions.

4. Alloy 926 Core Performance Advantages

4.1 Superior Local Corrosion Resistance

Benefiting from high molybdenum and nitrogen synergistic strengthening, UNS N08926 exhibits exceptional resistance to pitting and crevice corrosion. Its pitting resistance equivalent (PRE) is far higher than ordinary stainless steels and Alloy 904L, effectively avoiding local corrosion failure in high-chloride seawater and brine environments.

4.2 Excellent Stress Corrosion Cracking Resistance

The high-nickel austenitic matrix structure greatly inhibits chloride-induced stress corrosion cracking, which is a common defect of 300-series stainless steels. Alloy 926 remains structurally intact under high-temperature, high-pressure and high-salinity alternating service conditions, ensuring long-term equipment safety.

4.3 Outstanding Uniform Corrosion Resistance

Alloy 926 delivers stable corrosion resistance in dilute sulfuric acid, phosphoric acid, organic acids, neutral saltwater and industrial flue gas desulfurization media. It resists oxidation and acid erosion in complex chemical environments, providing more reliable protection than conventional corrosion-resistant stainless steels.

4.4 Optimized Structural Strength & Stability

Nitrogen alloying significantly improves matrix strength and structural strength without sacrificing ductility and toughness. The alloy resists grain coarsening and harmful intermetallic precipitation during long-term service below 400°C, maintaining consistent mechanical properties and dimensional stability.

4.5 Reliable Processability & Weldability

In solution-annealed condition, UNS N08926 presents excellent hot forging, cold bending and precision machining performance. It can be welded by GTAW and GMAW processes with matched super austenitic welding wires, It can be welded via GTAW, GMAW and other conventional processes with matched super austenitic filler wires. Controlling heat input and ensuring rapid cooling through the sensitization temperature range are recommended to maintain full corrosion resistance and toughness for on-site pipeline installation and equipment fabrication.

5. C&N’s Product Range & Specifications

We supply a full range of ASTM/ASME standard Alloy 926 UNS N08926 finished products and semi-finished materials for harsh anti-corrosion industrial systems:

• Forged Pipe Fittings: Seamless elbows, equal/reducing tees, concentric/eccentric reducers, pipe caps; Size range: NPS 1/2 ~ NPS 48, Wall thickness: SCH10 ~ SCH160, customized heavy-wall corrosion-resistant fittings available
• Seamless Alloy Pipes & Tubes: Hot-finished and cold-drawn seamless tubes; Outer diameter: 16mm ~ 720mm, Wall thickness: 3mm ~ 90mm, custom fixed-length cutting service supported
• Plates, Sheets & Bars: Thick plates, thin sheets, round bars and flat bars, supporting custom forging blanks and precision CNC machining
• Anti-Corrosion Flanges & Custom Forgings: WN, SO, blind flanges and special-shaped structural forgings for harsh corrosive environments

Factory Quality Assurance: Full-batch PMI spectral inspection, mechanical property testing, hardness detection, UT/PT non-destructive testing and dimensional verification. All products are supplied with EN 10204 3.1 mill test certificates.

6. Main Application Fields

• Marine & Desalination Industry: Seawater desalination pipeline systems, offshore platform piping, seawater cooling system fittings, marine corrosion-resistant structural parts
• Flue Gas Desulfurization (FGD): Power plant desulfurization tower piping, flue gas duct components, acid mist corrosion-resistant equipment parts
• Chemical & Petrochemical Industry: Dilute acid reaction vessels, chemical wastewater pipelines, heat exchanger tubes, salt solution process piping
• Environmental Protection Engineering: Industrial wastewater treatment equipment, high-chloride sewage pipeline fittings, corrosive medium delivery systems
• Paper & Pulp Industry: Bleaching system piping, high-corrosion process equipment components, industrial anti-rust structural parts

7. Our Quality Control & Product Marking

All Alloy 926 UNS N08926 products are manufactured under strict ISO 9001 quality management system. Our standardized production and inspection workflow covers raw material spectral recheck → hot forming & solution heat treatment → mechanical performance testing → non-destructive flaw detection → dimensional inspection → laser marking & vacuum packaging.

Finished products are free from surface cracks, inclusions, laps and oxidation defects. Standard laser marking includes brand information, Alloy 926 / UNS N08926 grade, applicable industry standards, heat batch number, product dimensions and wall thickness, fully compliant with international high-end industrial procurement and third-party inspection requirements.

If you need more information about Incoloy 926 series product, contact us now!