UNS S31603 – Ultra-Low Carbon Austenitic Steel For Welded Corrosive Structures

Overview

UNS S31603 is the ultra-low carbon iteration of UNS S31600, with a carbon content limited to ≤ 0.03% to eliminate the risk of intergranular corrosion after welding or high-temperature exposure. It retains the same molybdenum (2.00-3.00%), chromium (16.00-18.00%), and nickel (10.00-14.00%) content as S31600, ensuring superior pitting and crevice corrosion resistance in chloride environments. The ultra-low carbon design enhances its toughness, particularly at low temperatures, and eliminates the need for post-weld heat treatment, making it ideal for large-scale welded structures in harsh corrosive conditions. It is non-magnetic, highly formable, and widely used in industries where weld integrity and corrosion resistance are critical.

Chemical Composition (wt%)

C ≤ 0.03, Cr: 16.00-18.00, Ni: 10.00-14.00, Mo: 2.00-3.00, Mn ≤ 2.00, Si ≤ 1.00, P ≤ 0.040, S ≤ 0.030, N ≤ 0.10

Typical Mechanical Properties (Annealed Condition)

Tensile Strength (Rm): ≥ 485 MPa; Yield Strength (Rp0.2): ≥ 170 MPa; Elongation (A): ≥ 40%; Brinell Hardness (HB): ≤ 217

Core Advantages

Ultra-low carbon content prevents intergranular corrosion in welded joints; no post-weld heat treatment required; excellent pitting and crevice corrosion resistance in chloride-rich environments; superior low-temperature toughness; non-magnetic and highly formable; suitable for large welded structures and cryogenic applications.

Applications

Seawater desalination plants, large welded chemical storage tanks, pharmaceutical and food processing pipelines, offshore platform structures, cryogenic storage vessels, and medical instruments requiring high weldability and corrosion resistance.

Equivalent Grades

EN 1.4404, STS316L, GB 022Cr17Ni12Mo2, AISI 316L, SUS316L

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.