Natural Steels

 

UNS S31254 (SMO 254) Square Bars are high-performance super-austenitic stainless steel components designed for extreme environments. Often referred to as "6% Moly" due to their high molybdenum content, these bars provide exceptional resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking. 

 

Key Specifications and Properties

These square bars are typically manufactured to meet ASTM A276 or ASME SA276 standards. 

·         Chemical Composition: Includes 19.5–20.5% Chromium, 17.5–18.5% Nickel, and 6.0–7.0% Molybdenum.

·         Mechanical Strength: Offers approximately twice the strength of standard 300-series stainless steels.

o    Minimum Tensile Strength: 650 MPa (94 ksi).

o    Minimum Yield Strength: 300 MPa (44 ksi).

·         Corrosion Resistance: High Pitting Resistance Equivalent (PREn) value of 42–44, making it highly effective in seawater and acidic media

Common Sizes and Availability

UNS S31254 square bars are available in a wide range of dimensions to suit various industrial needs: 

·         Standard Size Range: Common side widths range from 4 mm to 100 mm, though some suppliers offer custom sizes up to 1200 mm.

·         Lengths: Typically available in 1 to 6-meter lengths or custom-cut to specific requirements.

·         Finishes: Available in various surface conditions including Black, Bright Polished, Rough Turned, and Matt Finish.

Applications

Because of its superior durability in aggressive environments, this material is widely used in:

 

·         Marine & Offshore: Seawater cooling systems, desalination plants, and offshore oil/gas platforms.

·         Chemical Processing: Equipment for handling acids, salts, and high-temperature corrosive media.

·         Pulp & Paper: Bleach plant equipment and tall oil distillation columns.

·         Energy: Flue gas desulfurization (FGD) scrubbers in power plants.

SMO 254 Seamless

Size ranging from: 6 mm OD to 914.4 mm OD and 1 mm to 50 mm thick.

SMO 254 Round Bar Size ranging from: 5 mm to 1200 mm

Nickel Alloy Seamless Tube Grade 200

size 1/8" NB TO 4"NB 
Sch 5 to Sch 40

Nickel Alloy Pipe 201

Size: 10mm to 508mm
Thickness: 1mm to 30mm

Nickel Pipe 201

Nickel Alloy Pipe and Tube Grade 205

Size: OD 10mm to 508MM
Thk: 1mm to 30mm

 

Nickel Alloy 200 welded tubing is a commercially pure wrought nickel product ( purity) known for its excellent resistance to corrosion, particularly from caustic alkalis. Unlike seamless options, welded Grade 200 tubes are fabricated by rolling and welding sheets or coils, making them a cost-effective choice for large-diameter or low-to-medium pressure applications. 
🛠️ Key Technical SpecificationsWelded Nickel 200 (UNS N02200) is governed by specific international standards to ensure quality and consistency in demanding environments. Trio Steel +1

• Standard Specs: ASTM B730 (Welded Tubing) and ASTM B725 (Welded Pipe).
• Dimensions: Typically ranges from 6.35 mm to 152 mm OD for standard tubing; larger diameters up to 1219.2 mm are available for specialized piping.
• Common Forms: Round, square, rectangular, and "U" bent configurations.
• Weld Methods: Electric Resistance Welded (ERW), Electric Fusion Welded (EFW), and LSAW. 

🧪 Chemical & Mechanical PropertiesNickel 200 is valued for its high thermal and electrical conductivity, which are among the highest for commercial nickel alloys. Chemical Composition Mechanical Strength (Annealed)

• Tensile Strength: 462 MPa (67,000 psi).
• Yield Strength (0.2% Offset): 148 MPa (21,500 psi).
• Elongation: 45%.
• Density: 8.89 g/cm³. 

🏗️ Industrial ApplicationsDue to its unique ability to maintain product purity, it is a staple in industries handling food or sensitive chemicals. 

• Chemical Processing: Production of caustic soda and handling of dry fluorine.
• Food Processing: Equipment for handling oils and fatty acids while maintaining taste and color purity.
• Electronics: Leads for electronic parts and battery components due to high conductivity.
• Marine & Offshore: Resistant to corrosion in distilled and natural water. 

⚠️ Key Limitations & Alternatives

• Temperature Limit: Nickel 200 is generally limited to below 315°C (600°F). Above this temperature, carbon can precipitate as graphite, leading to embrittlement.
• Alternative: For high-temperature service (above 315°C), Nickel 201 is the preferred low-carbon variant.
• Welded vs. Seamless: While welded tubes are more affordable, seamless tubes are rated for higher pressures as they lack a heat-affected zone (HAZ). 

Nickel Alloy 201 welded tubing (UNS N02201) is the low-carbon version of Nickel 200. It is specifically engineered for high-temperature service where carbon content must be kept below 0.02% to prevent graphitization and subsequent embrittlement.

��️ The High-Temperature AdvantageThe critical difference between Grade 200 and Grade 201 is their maximum operating temperature.

• Service Range: Approved for use up to 677°C (1250°F) under ASME code.
• Carbon Control: Maximum carbon of 0.02% prevents intergranular precipitates that cause brittleness.
• Ductility: Slightly more ductile and has a lower work-hardening rate than Nickel 200, making it easier to cold-form. Amardeep Steel Centre +3

��️ Standards & DimensionsWelded Grade 201 tubing follows standard industrial specifications for fabrication and testing. 

• Key Specs: ASTM B730 (Welded Tube) and ASTM B725 (Welded Pipe).
• Sizes: Common OD ranges from 6.35 mm to 152 mm for tubing, with welded pipe reaching up to 48 inches.
• Fabrication: Available as Round, Square, Rectangular, and custom "U" bent forms. 
• �� Common Industrial Uses
  • Chlor-Alkali Process: Handling sodium hydroxide (caustic soda) at high temperatures.
  • Chemical Reactors: Production of synthetic fibers and handling of fluorine or hydrochloric acid gas.
  • Aerospace: Used in high-temperature structural components and engine parts.
  • Food Processing: Large-scale evaporators for fatty acids and food juices where heat is a factor.

Nickel Alloy 205 (UNS N02205) is a specialized version of commercially pure nickel designed specifically for the electronics industry. It is a welded or seamless tube product that differs from Grades 200 and 201 through controlled chemical additions that enhance electron emission and mechanical strength under heat.🔬 Specialized Chemical CompositionGrade 205 is modified with small, precise amounts of magnesium and titanium to improve performance in vacuum environments.

• Nickel (Ni): 
• Magnesium (Mg): 0.01% – 0.08% (Acts as a deoxidizer and improves electron emission).
• Titanium (Ti): 0.01% – 0.05% (Increases strength at elevated temperatures).
• Carbon (C): 
• Silicon (Si): 

⚡ Key Performance CharacteristicsWhile it shares the high thermal and electrical conductivity of Grade 200, its specific alloying makes it superior for electrical components.

• Magnetostrictive Properties: Responds well to magnetic fields, useful for ultrasonic devices.
• Curie Temperature: Maintains a high Curie point (), ensuring stable magnetic properties.
• Oxidation Resistance: The titanium and magnesium additions provide a more stable surface oxide layer than pure nickel.
• Vapor Pressure: Exhibits very low vapor pressure, which is critical for maintaining high vacuum integrity in electronic tubes.

🏗️ Industrial ApplicationsGrade 205 welded tubing is almost exclusively used in high-precision electrical and laboratory environments.

• Vacuum Tubes: Used for cathodes, anodes, and structural supports in power tubes.
• Grid Side Rods: Components in radio and microwave transmitting tubes.
• Transducer Components: Utilized in ultrasonic equipment due to magnetostrictive properties.
• Lead Wires: High-purity electrical leads for incandescent and discharge lamps.

SMO 254 WELDED and Size ranging from: 6 mm OD to 914.4 mm OD and 0.3 mm to 50 mm thick.

SMO 254 Reducer and Size ranging from: Seamless Butt Weld Fittings: 12? � 10?, Welded Butt Weld Fittings: 12? � 48?

SMO 254 Elbow and Size ranging from: Seamless Butt Weld Fittings: 12? � 10?, Welded Butt Weld Fittings: 12? � 48?

TITANIUM GRADE 1 and Size ranging from: 6 mm OD to 914.4 mm OD and 0.3 mm to 50 mm thick.

SMO 254 HEX Bar Size ranging from: 5 mm to 1200 mm

Any size from 0.01mm thickness to 100mm thickness

SMO 254 circle ring size: 3" to 38"

SMO 254 WIRE Size ranging from: 0.1 mm to 5 mm

SMO 254 FLANGES SIZE 1' NB TO 1000 " NB

SMO 254 BOLTS NUTS STUDS WASHER SIZE: AS PER YOUR REQUIREMENT