309S Stainless Steel Plate

309S Stainless Steel Plate thrives where temperatures soar-up to 1.100°C (2.012°F). With a chromium-nickel balance (23% Cr, 13% Ni) optimized for cyclic heating, it resists scaling, carburization, and sulfidation in furnaces, exhaust systems, and pyrolysis units. A cost-effective alternative to 310S and Inconel, it's the backbone of industries where thermal shock is a daily challenge.

Why 309S Outperforms in Red-Hot Conditions

Oxidation Shield

Forms a stable Cr₂O₃ layer at 900°C+ (50% slower scaling vs. 304H).

Thermal Fatigue Fighter

Survives 5.000+ rapid heat-cool cycles (ASTM E606 verified).

Carburization Barrier

Blocks carbon ingress in ethylene cracker tubes (API 934 compliant).

Weld-Safe Design

Low carbon (0.03% max) prevents HAZ cracking in high-heat joints.

Critical High-Temp Metrics

Industry-Specific Dominance

1. Petrochemical Processing

Cracking furnace tubes | Sulfur recovery unit liners

2. Heat Treatment

Annealing trays | Carburizing furnace muffles

3. Energy Generation

Boiler baffle plates | Waste incinerator internals

4. Automotive Exhaust

Turbocharger housings | Diesel particulate filter shells

Global Success Stories

Qatar Gas Refinery: "309S plates doubled pyrolysis tube lifespan vs. 304H."

Bavarian Heat Treat Co.: "Cut furnace muffle replacement costs by 40% annually."

Detroit Auto Supplier: "Eliminated exhaust warping in -40°C to 800°C cycles."

Fabrication Expertise

Q: Best welding practice for 309S-to-carbon steel joints?

A: Use ER309L filler with 60–80°C preheat; avoid post-weld stress relief.

Q: Surface finish for oxidation resistance?

A: Mill finish (2B) outperforms polished surfaces in scaling tests.

Q: Minimum thickness for furnace applications?

A: 6mm for structural parts | 3mm for shielding with ceramic coatings.

Common Surfaces

Stainless Steel Standards Comparison Table