SUS347 – Niobium-Stabilized Austenitic Steel: Welded High-Temp Component Expert

Overview

SUS347 is a niobium-stabilized austenitic stainless steel, designed to eliminate intergranular corrosion in welded components and high-temperature service. By adding niobium (Nb + Ta: 8×C~1.00%), it forms stable niobium carbides, which prevent the formation of chromium carbides and maintain corrosion resistance even after exposure to temperatures between 430-900°C. Unlike titanium-stabilized grades, it offers better high-temperature strength and toughness, making it suitable for demanding welded applications. With 17.00-19.00% chromium and 9.00-13.00% nickel, it forms a stable austenitic structure, is non-magnetic, and has excellent weldability and formability.

Chemical Composition (wt%)

C ≤ 0.08, Si ≤ 1.00, Mn ≤ 2.00, P ≤ 0.045, S ≤ 0.030, Cr: 17.00-19.00, Ni: 9.00-13.00, Nb + Ta: 8×C~1.00

Typical Mechanical Properties (Annealed Condition)

Tensile Strength (Rm): ≥ 550 MPa; Yield Strength (Rp0.2): ≥ 210 MPa; Elongation (A): ≥ 40%; Brinell Hardness (HB): ≤ 205

Core Advantages

Niobium stabilization prevents intergranular corrosion in welds and high-temperature service; excellent high-temperature creep strength and oxidation resistance; non-magnetic; good weldability and formability; superior toughness compared to titanium-stabilized grades.

Applications

Aerospace exhaust manifolds, chemical processing equipment, high-temperature heat exchangers, boiler components, nuclear processing piping, and welded structural parts.

Equivalent Grades

UNS S34700, STS347, EN 1.4550, GB 06Cr18Ni11Nb, AISI 347

Stainless Steel Suppliers

If you have project requirements for stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.