About ER 347 Core Wire

ER 347 core wire is a type of welding electrode designed for welding stabilized austenitic stainless steels, such as 321 and 347. It offers excellent resistance to intergranular corrosion, high-temperature strength, and weldability, making it suitable for applications in the aerospace, chemical, and food processing industries.

ER 347 Core Wire Chemical Compositions:

  • Chromium (Cr): Constitutes approximately 17-20%, providing corrosion resistance and stability at elevated temperatures.
  • Nickel (Ni): Comprises around 9-13%, enhancing toughness and resistance to corrosion and oxidation.
  • Niobium (Nb): Typically present in amounts of 10 times the carbon content, stabilizing the weld structure and preventing carbide precipitation.
  • Carbon (C): Limited to a maximum of 0.08%, minimizing the formation of carbides and preserving corrosion resistance.
  • Manganese (Mn): Usually around 1-2%, aiding in deoxidation and enhancing strength and ductility.
  • Silicon (Si): Present in trace amounts, aiding in deoxidation and improving weld pool fluidity.
  • Phosphorus (P) and Sulfur (S): Kept at very low levels to prevent brittleness and impurities in the weld metal.

ER 347 Core Wire Physical Properties:

  • Tensile Strength: ER 347 exhibits high tensile strength, typically ranging from 550 to 750 MPa, providing structural integrity in welded joints.
  • Elongation: It possesses good elongation properties, typically between 35% to 45%, allowing for flexibility and deformation resistance in welded components.
  • Hardness: ER 347 maintains a balanced hardness, with values typically in the range of 180 to 220 HB (Brinell hardness), suitable for various applications requiring both strength and machinability.
  • Ductility: This core wire offers good ductility, with a reduction in area typically exceeding 50%, ensuring that welds can withstand deformation without cracking or failure.
  • Magnetic Permeability: ER 347 exhibits low magnetic permeability, making it suitable for applications requiring non-magnetic properties, such as in medical devices or electronic equipment.
  • Density: The density of ER 347 is approximately 8.0 g/cm³, similar to that of other austenitic stainless steels, providing a good balance of strength and lightweight properties in welded structures.
  • Thermal Conductivity: It has a relatively high thermal conductivity, facilitating efficient heat transfer during welding processes and reducing the risk of heat-affected zone (HAZ) defects.
  • Electrical Conductivity: ER 347 typically has moderate electrical conductivity, suitable for applications requiring electrical conductivity, such as in electrical enclosures or components.

ER 347 Core Wire Mechanical Properties:

  • Yield Strength: ER 347 exhibits a high yield strength, typically ranging from 290 to 380 MPa, providing structural stability under load.
  • Ultimate Tensile Strength (UTS): It demonstrates excellent ultimate tensile strength, typically ranging from 620 to 800 MPa, offering resilience to mechanical stress and ensuring the integrity of welded joints.
  • Impact Toughness: ER 347 shows good impact toughness, with Charpy V-notch impact values typically exceeding 100 J at room temperature, resisting fracture under sudden loads and providing durability in demanding applications.
  • Fatigue Resistance: This core wire offers resistance to fatigue failure, maintaining performance over repeated loading cycles and ensuring reliability in cyclically loaded structures.
  • Creep Resistance: ER 347 provides resistance to creep deformation under sustained loads at elevated temperatures, ensuring long-term structural integrity in high-temperature applications such as in the petrochemical or power generation industries.
  • Hardness: ER 347 maintains a balanced hardness, typically ranging from 180 to 220 HB (Brinell hardness), providing a good combination of strength and machinability in welded components.
  • Fracture Toughness: It exhibits good fracture toughness, with critical stress intensity factor values typically exceeding 30 MPa√m, indicating its ability to resist crack propagation and ensure the reliability of welded structures in service.

ER 347 Core Wire Applications:

  1. Petrochemical: Used for welding components in refineries, chemical processing plants, and pipelines due to its resistance to corrosion and high-temperature environments.
  2. Aerospace: Employed in the fabrication of aircraft components and structures requiring high strength and corrosion resistance.
  3. Power Generation: Used for welding boilers, heat exchangers, and turbine components in power plants due to its resistance to high temperatures and corrosion.
  4. Food Processing: Utilized in equipment fabrication for food processing and storage, meeting sanitary standards and offering corrosion resistance.
  5. Medical Devices: Applied in the fabrication of medical instruments and implants due to its biocompatibility and corrosion resistance.
  6. Automotive: Used for welding components in exhaust systems, catalytic converters, and other parts requiring resistance to high temperatures and corrosion.
  7. Chemical Processing: Employed in the fabrication of reactors, vessels, and piping systems requiring resistance to corrosive chemicals.
  8. Oil and Gas: Utilized for welding pipelines, offshore platforms, and equipment in corrosive environments in the oil and gas industry.
  9. Construction: Used for welding structural components requiring durability and resistance to corrosion, such as bridges and building frameworks.
  10. General Fabrication: Applied in various general fabrication applications where high strength and corrosion resistance are required.