347 stainless steel wire mesh
347 (UNS S34700 | EN 1.4550 | AISI 347) stainless steel mesh is a niobium-stabilized(Nb) austenitic stainless steel , also commonly referred to as Columbium (Cb) . Like 321 (which uses Titanium), 347 is designed to prevent sensitization and intergranular corrosion.
The Niobium combines preferentially with carbon, forming niobium carbides and leaving chromium in solution to provide corrosion resistance. This makes 347 the preferred choice for applications involving extended exposure to high temperatures or when the material cannot be annealed after welding.
Non-magnetic in annealed condition; slightly magnetic after cold working
Typical Chemical Composition:
Grade | C | Cr | Ni | Nb | Mn | Si | P | S | Fe |
347 | ≤0.08% | 17.0–19.0% | 9.0–13.0% | 10×C min, ≤1.00% | ≤2.0% | ≤1.0% | ≤0.045% | ≤0.030% | Balance |
(Note: The Niobium content is typically at least 10 times the Carbon content, providing stronger stabilization than the 5:1 ratio used in 321.)
Key Properties of 347 Wire Mesh
· Physical Properties
Density: 7.98 g/cm³
Melting Point: 1398-1454°C (Service temperature: -196°C ~ 950°C)
Thermal Conductivity: 16.2 W/m·K (at 100°C)
Electrical Resistivity: 0.73 x 10^-6 Ω·m (at 20°C)
· Mechanical Properties
Tensile Strength: 620-860 MPa
Yield Strength: ≥310 MPa
Elongation: ≥20%
Hardness: ≤295 HB
· Corrosion Resistance
Excellent resistance to general corrosion
Good resistance to intergranular corrosion after welding
Resistant to pitting and crevice corrosion in chloride environment
Outstanding high-temperature strength and oxidation resistance up to 950°C
Good creep resistance under high temperature
Typical Applications
347 mesh is specified for critical components in power generation, petrochemical processing, and heavy industrial heating where failure is not an option.
· Power Generation: Superheater tubes, reheater tubes, and steam line components.
· Petrochemical Processing: Catalyst support grids, reactor internals, and furnace parts exposed to high temperatures and corrosive gases.
· Aerospace: Exhaust components, manifold gaskets, and afterburner parts.
· Heat Treatment: Heavy-duty furnace baskets, trays, and fixtures subjected to constant stress at high temperatures.
· Welded Fabrications: Any large or heavy welded structure that will operate in the sensitization temperature range and cannot be annealed after welding.
Comparison: 347 Vs 321 Stainless Steel
Feature | 347 | 321 |
Stabilizing Element | Niobium (Columbium) | Titanium |
Stabilization Ratio | ≥ 10 x C% | ≥ 5 x C% |
High-Temp Strength | Higher (better creep resistance) | Good |
Weldability (Heavy Sections) | Preferred (Ti can burn off) | Good (best for light sections) |
Aqueous Corrosion | Similar to 304 | Similar to 304 |
Cost | High | Medium-High |
Best Use | Power generation, heavy petrochem, sustained high heat | Aircraft exhaust, general high-heat, thermal cycling |
