SUS439 – Titanium-Stabilized Ferritic Alloy For Welded High-Temp Components

Overview

SUS439 is a titanium-stabilized ferritic stainless steel under JIS G 4303/G 4304, developed to eliminate intergranular corrosion in welded components without post-weld annealing. With 17.00-19.00% chromium and 0.10-0.30% titanium, it offers superior corrosion and oxidation resistance compared to SUS430, particularly in chloride-containing and high-temperature environments. It is magnetic, has good formability and thermal conductivity, and is suitable for large welded structures due to its stable weld integrity. Its balanced composition makes it a cost-effective choice for welded industrial components requiring reliable high-temperature performance.

Chemical Composition (wt%)

C ≤ 0.07, Cr: 17.00-19.00, Ti: 0.10-0.30, Mn ≤ 1.00, Si ≤ 1.00, P ≤ 0.040, S ≤ 0.030, Ni ≤ 0.50, N ≤ 0.040

Typical Mechanical Properties (Annealed Condition)

Tensile Strength (Rm): ≥ 455 MPa; Yield Strength (Rp0.2): ≥ 296 MPa; Elongation (A): ≥ 32%; Brinell Hardness (HB): ≤ 170

Core Advantages

Titanium stabilization prevents intergranular corrosion in welds; no post-weld annealing required; superior corrosion and oxidation resistance compared to SUS430; good weldability and formability; magnetic with excellent thermal conductivity; suitable for high-temperature service (up to 760°C); cost-effective for welded structures.

Applications

Welded heat exchangers, boiler components, automotive exhaust manifolds, industrial piping, chemical processing equipment, commercial kitchen appliances, and large welded structural parts in mild to moderate corrosive environments.

Equivalent Grades

EN 1.4510, UNS S43900, GB 022Cr18Ti, AISI 439

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.