Grade 441 (1.4509 / UNS S43932 / SUS441) is a titanium & niobium dual-stabilized ultra-low carbon ferritic stainless steel strip. It contains no nickel, with 17.5%–18.5% chromium matched with Ti and Nb composite stabilizing elements. Compared with conventional 409L and 436L ferritic stainless steel, 441 features superior high-temperature oxidation resistance, outstanding thermal fatigue performance and excellent weld anti-intergranular corrosion property.

With low thermal expansion coefficient and high thermal conductivity, 441 stainless steel strip is the cost-preferred material for automotive exhaust systems, condensing boilers, household high-temperature appliances, heat exchangers and waste gas flue components. All finished strips are produced via cold rolling, continuous bright annealing, pickling, precision slitting and strict non-destructive inspection, featuring flat surface, uniform thickness, stable dimensional tolerance and excellent stamping & roll forming performance.

2. Global Equivalent Grade Cross Reference

Note: All equivalent grades adopt Ti+Nb dual stabilization design, fully interchangeable for automotive and high-temperature industrial manufacturing.

3. Chemical Composition (wt%, Standard Limit Range)

Composition Core Advantages

Ultra-low carbon and nitrogen (C≤0.03%, N≤0.03%): Greatly reduce chromium carbide precipitation risk during welding and long-time high-temperature exposure.

Ti + Nb dual composite stabilization: Ti and Nb preferentially combine carbon and nitrogen to form stable carbides and nitrides, completely eliminate weld intergranular corrosion without post-weld annealing treatment.

17.5%–18.5% chromium content: Forms dense anti-oxidation passive film, far better anti-rust and anti-scaling capacity than 409L and 430 under high-temperature cyclic heating conditions.

Nickel-free alloy design: Effectively avoid cost fluctuation caused by nickel price volatility, much more economical than 304 austenitic stainless steel.

Strict low sulfur control (S≤0.015%): Prevent hot cracking during deep drawing, roll forming and continuous welding.

4. Physical & Mechanical Properties

4.1 Basic Physical Properties (Room Temperature, Fully Annealed Condition)

●Density: 7.75 g/cm³
●Melting Temperature Range: 1420 ~ 1450 ℃
●Thermal Conductivity (20℃): 26.0 W/m·K (Much higher than 304, excellent heat dissipation)
●Linear Thermal Expansion Coefficient (20–700℃): 11.5 ×10⁻⁶ /℃ (30% lower than 304, less thermal deformation under temperature fluctuation)
●Elastic Modulus E: 200 GPa
●Shear Modulus G: 76 GPa
●Poisson’s Ratio: 0.23
●Magnetism: Fully magnetic (intrinsic ferritic structure, magnetism cannot be eliminated by annealing)
●Long-term Continuous Service Temperature: Up to 750℃
●Short-term Peak Temperature Resistance: 950℃

4.2 Room–Temperature Mechanical Properties (Annealed Cold Rolled Strip, Minimum Standard Value)

High-Temperature Performance Highlights
Outstanding thermal fatigue resistance: Resist cracking under repeated heating and cooling cycles, ideal for long-running exhaust pipeline equipment.
Stable high-temperature creep strength: Less permanent deformation under sustained high-temperature load compared with 409L.
No brittle sigma phase precipitation between 400–800℃, maintaining stable mechanical performance for long-cycle service.

5. Standard Sizes, Thickness & Width Range

5.1 Thickness Classification

Ultra-thin precision strip: 0.05 mm ~ 0.30 mm
Conventional cold rolled strip: 0.15 mm ~ 6.00 mm

5.2 Width Specification

Slit narrow strip: 10 mm ~ 600 mm
Wide coil mother strip: 1000 mm / 1219 mm / 1250 mm / 1500 mm

5.3 Supply Forms

Full-width coil, precision slit narrow strip, cut flat sheets, stamping blanks

5.4 Thickness Tolerance

Standard industrial strip: ±0.02 ~ ±0.05 mm
High-precision thin strip: ±0.003 ~ ±0.01 mm

6. Common Surface Finishes

2B Annealed & Pickled Surface (Most Popular Grade) Uniform silver matte surface, flat and clean, excellent formability and weldability. Widely used for automotive muffler shells, exhaust stamping parts, boiler flue pipes.

2D Dark Matte Surface Thin uniform oxide layer, low cost, applied to hidden internal structural components without appearance requirements.

BA Bright Annealed Surface Semi-mirror smooth finish without oxidation film, for high-end oven inner liners and visible heating decorative parts.

No.4 Brushed Hairline Surface Continuous linear grain texture, optional anti-fingerprint coating, used for household oven exterior decorative panels.

1D Hot Rolled Pickled Surface Only for thick strip over 3.0mm, gray matte surface, for heavy industrial furnace support components.

7. Standard Edge Types

Slit Edge Smooth straight edge with tiny minimal burr, standard for cold rolled coils, suitable for continuous stamping and roll forming.

Deburred Ground Edge Fully burr-free polished edge, adopted for precision automotive exhaust stamping parts to avoid die scratching.

Chamfered / Rounded Edge Edge rounded or 45° chamfered, prevent mold damage during high-speed automated stamping production.

8. Core Product Features

Excellent High-Temperature Oxidation & Thermal Fatigue Resistance Stable anti-scaling performance under 750℃ long-term operation, perfectly fit cyclic heating environment of exhaust flues; superior performance than 409L, 430 and 436L.

Superior Weldability & Anti-Intergranular Corrosion Ti-Nb dual stabilization eliminates grain boundary corrosion at welding seams; no post-weld heat treatment required for mass welding, greatly cutting processing cost.

Low Thermal Expansion & High Thermal Conductivity Minimal thermal deformation during temperature rise and drop, fast heat dissipation, ideal raw material for heat exchanger and heat conduction components.

Good Stamping & Deep Drawing Performance Sufficient elongation rate, supports complex bending, curling and deep forming without cracking, applicable to intricate automotive exhaust stamped parts.

Remarkable Cost Advantage Nickel-free alloy composition, stable raw material price, 30%–50% lower material cost than 304 strip for high-temperature applications.

Reliable Atmospheric & Fresh Water Corrosion Resistance Satisfy service demands of outdoor equipment, kitchen appliances and boiler condensate environments; not recommended for long-term chloride-rich seawater or salt spray conditions (select 316L strip for coastal corrosive scenarios).

RoHS & IMDS Automotive Compliant Low harmful heavy metal content, non-toxic, fully comply with global auto parts export environmental standards.

9. Typical Applications

9.1 Automotive Exhaust System (Main Application)

Muffler shells, exhaust pipes, catalytic converter housings, EGR pipelines, heat shields, exhaust manifold inner liners, tail pipe stamping blanks.

9.2 Household High-Temperature Appliances

Oven inner liners, gas stove burner components, water heater inner tanks, range hood high-temperature flues, electric heating tube outer casings.

9.3 Industrial Heat Exchange & Boiler Equipment

Condensing boiler flue tubes, heat exchanger fin strips, industrial furnace inner linings, waste heat recovery thin shells, biomass boiler anti-oxidation liners.

9.4 Environmental Protection & Ventilation Equipment

Low-temperature flue ducts of waste incinerators, air heater internal parts, industrial waste gas pipelines, high-temperature dust removal equipment shells.

9.5 Architectural & Heating Decoration

Outdoor heating equipment decorative panels, fireplace inner liners, solar heat collecting thin strips, anti-rust high-temperature thin support parts.

10. Grade Comparison Chart

11. Usage Notes

Chloride environment limitation: Not suitable for long-term immersion in seawater, salt fog or bleach; select 316L strip for coastal corrosive working conditions.

Magnetic property explanation: Permanent magnetism is inherent ferritic characteristic, it will not affect mechanical and high-temperature service performance, demagnetization treatment is unavailable.

Welding matching suggestion: Adopt special welding wire for ferritic stainless steel to avoid weld embrittlement; thin strip adopts TIG spot welding for better forming effect.

Temperature limit: Continuous working temperature shall not exceed 750℃; long-term service above 800℃ will accelerate surface oxidation and shorten service life.

Surface protection reminder: 2B and BA bright surfaces must be covered with PE protective film during slitting and stamping to prevent scratch damage.

12. Executive Standards & Export Certifications

Comply with ASTM A666, EN 10088-2, JIS G4305, GB/T 3280. Available supporting documents: MTC material test report, SGS third-party composition inspection, IMDS automotive filing data, , high-temperature oxidation resistance test report, fully meet global automotive and industrial equipment export procurement standards.

Contact Us 

ALLIN Metal is a professional manufacturer specializing in customized 441 Ti-Nb stabilized ferritic stainless steel coils and precision slit strips. We own complete production lines covering cold rolling, continuous bright annealing, precision slitting and full-surface inspection, capable of supplying customized thickness, width, surface finishes and full set of material test certificates for automotive exhaust, heating equipment and heat exchanger projects worldwide. With stable monthly output, strict quality control system and flexible delivery schedules, we provide cost-effective high-temperature ferritic stainless steel strips for global industrial buyers. If you have any procurement demands, please feel free to contact our professional sales team to obtain technical datasheets, factory quotations and bulk order support.