Bar and Rod
Plate and Sheet
Strip
Pipe and Tube
Wire
Welding
Powder Material
Cast Products
Forged Products
Fittings
Fastening
Round Bar:
φ2–500 mm, 1–6 m length
Flat/Square Bar:
4–100 mm thickness/width
Hex Bar:
A/F 3–100 mm
Hollow Bar:
OD 20–300 mm
Sheet:
0.3–6 mm thickness
Medium Plate:
6–25 mm thickness
Heavy Plate:
25–100 mm thickness
Standard Strip:
0.05–3 mm thick,
10–600 mm wide
Precision strip:
0.01–0.5 mm thick,
tight tolerance ±0.005 mm
Foil:
0.005–0.1 mm thick
Seamless Tube:
OD 6–450 mm,
WT 1–50 mm,
1–12 m length
Welded Tube:
OD 10–600 mm,
WT 1–20 mm
Capillary Tube:
OD 1–10 mm,
WT 0.1–2 mm
Wire Form:
Cold Drawn Wire,
Bright Wire,
Spring Wire,
Fine Wire,
Ultra-fine Wire
General Diameter:
φ0.1–10 mm
Coil Weight:
50–500 kg,
customizable tolerance
Solid Wire:
φ0.8–4.0 mm
Flux-cored Wire:
φ1.2–4.0 mm
Welding Rod:
φ2.0–5.0 mm
Powder Form:
AM 3D Printing Powder,
Spherical Powder,
Gas-atomized Powder,
Water-atomized Powder
Particle Size:
10–150 μm
Sphericity:
≥90% for AM grade
Cast Ingot:
φ200–800 mm
Precision Casting:
min wall 0.5 mm
Cast Pipe:
OD 100–600 mm,
WT 10–50 mm
Forged Bar:
Φ35–500 mm
Forged Ring:
OD 200–2000 mm
Forging Weight:
1–5000 kg
Fittings Form:
Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint
Size range:
1/2''–24'' (DN15–DN600)
Wall thickness:
Sch10–Sch160, STD, XS, XXS
Pressure Class:
150–2500 LB
Fastening Form:
Bolt, Nut, Screw, Stud, Washer, Pin, Rivet
Metric: M3–M64
Imperial: #4–2.5''
Length: 6–500 mm
441 is a dual-stabilized (niobium and titanium) ferritic stainless steel containing about 18% chromium and no deliberate nickel. This datasheet presents the material within the American (ASTM / ASME / UNS) standard system.
With nominally 18% chromium stabilized by both niobium and titanium, 441 provides good high-temperature strength — exceeding that of Types 409 and 439 — together with good oxidation and corrosion resistance in many exhaust-gas environments. The dual stabilization ties up carbon and nitrogen, preventing sensitisation and giving excellent weldability without post-weld annealing, while the niobium in solid solution improves elevated-temperature strength and creep resistance. Being ferritic and nickel-free, it is magnetic, cannot be hardened by heat treatment, is largely immune to chloride stress-corrosion cracking, and offers good formability for a ferritic grade.
Typical applications include hot-end automotive exhaust components (manifolds, flexible connectors, converters), heat-exchanger parts, and elevated-temperature equipment requiring strength and oxidation resistance at low cost.
Typical values, annealed condition.
| Property | Value | Unit |
|---|---|---|
| Density | 7.7 | g/cm³ |
| Melting range | 1480–1530 | °C |
| Elastic modulus | 220 | GPa |
| Coefficient of thermal expansion (20–100 °C) | 10.4 | µm/m·°C |
| Thermal conductivity (100 °C) | 25.0 | W/m·K |
| Specific heat (20 °C) | 460 | J/kg·K |
| Structure | Ferritic | — |
Specified per ASTM A240 (UNS S43940 / S43932).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Iron | Fe | Balance | — | Base element |
| Chromium | Cr | 17.5 | 18.5 | Corrosion / oxidation resistance |
| Niobium | Nb | 0.30 | 1.00 | Primary stabiliser; high-temperature strength |
| Titanium | Ti | 0.10 | 0.60 | Co-stabiliser; ties up C and N |
| Nickel | Ni | — | 0.50 | Residual |
| Manganese | Mn | — | 1.00 | Deoxidiser |
| Silicon | Si | — | 1.00 | Deoxidiser |
| Carbon | C | — | 0.030 | Low (stabilised, weldability) |
| Nitrogen | N | — | 0.030 | Low (stabilised) |
| Phosphorus | P | — | 0.040 | Residual impurity |
| Sulphur | S | — | 0.030 | Residual impurity |
Nominal: 18Cr dual-stabilized (Nb + Ti) ferritic stainless steel; Nb + Ti ≥ 0.20 + 4×(C+N).
Annealed condition, per ASTM A240 for UNS S43940 / S43932.
| Condition | Property | Value |
|---|---|---|
| Annealed | Tensile strength (UTS) | ≥430 MPa |
| Annealed | 0.2% yield strength | ≥205 MPa |
| Annealed | Elongation at break | ≥18 % |
| Annealed | Hardness | ≤217 HB (~95 HRB) |
| — | Elastic modulus | 220 GPa |
Confirm against the mill test report. High-temperature strength exceeds Types 409 and 439 owing to solid-solution niobium.
| Environment | Performance | Notes |
|---|---|---|
| Atmospheric / general | Very Good | Comparable to 304 in many media |
| Exhaust-gas / condensate | Very Good | Designed for hot-end exhaust |
| Chloride stress-corrosion cracking | Very Good | Ferritic — largely immune |
| Pitting / crevice corrosion | Moderate | Below molybdenum-bearing grades |
| Oxidation (elevated temperature) | Very Good | Superior to 409 / 439; useful to ~950 °C |
Corrosion resistance is comparable to 304 in many environments, with the advantage of immunity to chloride stress-corrosion cracking and superior high-temperature strength among the standard ferritics.
A ferritic grade; cannot be hardened by heat treatment. Properties are set by annealing.
Anneal Heat to approximately 815–950 °C and air cool. Owing to dual stabilization, post-weld annealing is not required to restore intergranular corrosion resistance. Avoid prolonged exposure near 475 °C (embrittlement).
Excellent weldability without sensitisation owing to dual (Nb + Ti) stabilization; post-weld annealing is not required. The weld retains base-metal corrosion resistance and most mechanical properties.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Very Good | AWS A5.9 ER439 / stabilized ferritic, or Ni-base |
| GMAW / MIG | Good | Stabilized ferritic filler |
| Resistance / seam | Very Good | — |
Use a stabilized stainless or nickel-base filler to maintain weld-metal corrosion resistance. No post-weld anneal required.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Machinability | Good; similar to other ferritic grades |
| Work hardening | Low rate — good formability |
| Coolant | Ample flood coolant |
Forming Processes
| Process | Notes |
|---|---|
| Cold forming | Good — bending, roll forming, deep drawing |
| Hot forming | ~1100–800 °C; anneal afterward |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Automotive | Exhaust manifolds, flexible connectors, converters | High-temperature strength + oxidation resistance |
| Heat transfer | Heat-exchanger components | Thermal stability + corrosion resistance |
| Elevated temperature | Furnace and burner parts | Oxidation resistance + creep strength |
| General industrial | Welded and formed components | SCC resistance + weldability |
| Product Form | ASTM Standard | ASME Code |
|---|---|---|
| Plate, sheet and strip | ASTM A240 | ASME SA-240 |
| Seamless / welded tube | ASTM A268 | ASME SA-268 |
| Bar and shapes | ASTM A479 | — |
| Welding consumables | AWS A5.9 ER439 | — |
Dual-stabilized (Nb + Ti) ferritic stainless steel. UNS S43940 / S43932.
| Grade | Cr % | Stabiliser | C % | Best Used For |
|---|---|---|---|---|
| 441 | 17.5–18.5 | Nb + Ti | ≤0.03 | 18Cr dual-stabilized ferritic; hot exhaust, high-T strength |
| 439 | 17–19 | Ti | ≤0.07 | 18Cr-Ti ferritic; cold-end exhaust |
| 409L | 10.5–11.7 | Ti | ≤0.03 | 11Cr muffler-grade ferritic |
| 430 | 16–18 | — | ≤0.12 | General ferritic; non-stabilized |
| 444 | 17.5–19.5 | Ti / Nb | ≤0.025 | 18Cr-2Mo ferritic; higher corrosion resistance |
021-33556635
13371897780
651280525@qq.com
No. 600, Si Chuang Road, Songjiang District, Shanghai
