About ER 347 Sub Arc Wire

ER 347 sub arc wire is a stabilized stainless steel welding wire containing columbium (niobium). It prevents carbide precipitation, enhancing resistance to intergranular corrosion. Ideal for welding 347 and 321 stainless steels, it is commonly used in high-temperature applications, such as power generation and chemical processing equipment.

ER 347 Sub Arc Wire Chemical Compositions:

The chemical composition of ER 347 sub arc wire typically includes:

  • Chromium (Cr): 19-21%
  • Nickel (Ni): 9-11%
  • Carbon (C): ≤ 0.08%
  • Manganese (Mn): 1-2%
  • Silicon (Si): ≤ 1%
  • Phosphorus (P): ≤ 0.03%
  • Sulphur (S): ≤ 0.03%
  • Columbium (Niobium, Cb/Nb): 8-10 times the carbon content or 0.2-1.0%
  • Iron (Fe): Balance

ER 347 Sub Arc Wire Physical Properties:

ER 347 sub arc wire has notable physical properties:

  1. Density: Approximately 7.9 g/cm³, providing the mass per unit volume of the material.
  2. Melting Point: Around 1400 to 1425°C, ensuring it melts uniformly during welding for a strong bond.
  3. Coefficient of Thermal Expansion (CTE): About 17.2 µm/m°C, relevant for managing thermal expansion in welded structures.
  4. Thermal Conductivity: Approximately 16.3 W/m·K, indicating efficient heat transfer during welding.
  5. Electrical Resistivity: Roughly 72 µΩ·cm, affecting the electrical current during the welding process.
  6. Magnetic Permeability: Low, making it suitable for applications where non-magnetic properties are needed.

These properties make ER 347 sub arc wire a reliable choice for welding applications requiring stability under high temperatures and resistance to thermal fatigue.

ER 347 Sub Arc Wire mechanical Properties:

ER 347 sub arc wire exhibits strong mechanical properties:

  1. Tensile Strength: Typically around 550-750 MPa, indicating the maximum stress the material can withstand while being stretched or pulled.
  2. Yield Strength: Approximately 250-400 MPa, representing the stress at which the material begins to deform plastically.
  3. Elongation: Around 35-45%, reflecting its ability to stretch before breaking, contributing to its ductility.
  4. Impact Toughness: Good impact resistance, ensuring the welds can absorb energy from shocks or sudden forces without fracturing.
  5. Hardness: Typically in the range of 160-200 HV (Vickers hardness), indicating the material’s resistance to deformation or indentation.
  6. Creep Resistance: Excellent, maintaining its structural integrity under prolonged exposure to high temperatures.

ER 347 Sub Arc Wire Applications:

  1. Aerospace Industry – High-temperature components and structures.
  2. Chemical Processing Equipment – Vessels and pipes handling corrosive materials.
  3. Power Generation – Boilers, heat exchangers, and super heaters.
  4. Petrochemical Industry – Reactors and catalytic crackers.
  5. Food Processing Equipment – Sanitary environments requiring corrosion resistance.
  6. Pharmaceutical Industry – Sterile and clean room environments.
  7. Cryogenic Vessels – Low-temperature storage tanks and piping systems.
  8. Nuclear Power Plants – Components exposed to high temperatures and radiation.