441 Stainless Steel (UNS S43940)
Ferritic (dual-stabilized) · EN 10088-2, ASTM A240/A240M · Density 7.7 g/cm³
Type 441 (EN 1.4509, UNS S43940) is a titanium- and niobium-stabilized ferritic stainless steel used for exhaust hot-end parts, welded tube and selected heat-transfer components. Dual stabilization supports fabrication and elevated-temperature use, while the actual component limit still depends on metal temperature, oxidation atmosphere, thermal fatigue, welds, thickness and design validation.
Quotation brief
Quote 441 When
Quote 441 when an exhaust hot-end, welded tube or heat-transfer component needs a higher-chromium, dual-stabilized ferritic route and the design has defined actual metal temperature and thermal fatigue. It is commonly compared with 409L, 439 and 304, but the decision must include gas chemistry, condensate, road salts, cycle frequency, weld geometry, forming severity and appearance. No fixed peak-temperature or pricing statement can approve the substitution.
Best fit
- Exhaust manifolds, front pipes and hot-end shells validated for measured metal temperature, thermal cycles, vibration and condensate exposure.
- Welded ferritic tube and formed parts that benefit from titanium-niobium stabilization under an approved fabrication procedure.
- Selected heat-exchanger or exterior components with finish samples, magnetic behavior and environmental limits accepted by the project.
Limits to check
- Published peak-temperature figures do not rate a manifold or tube because local stress, gas chemistry, section and thermal fatigue can govern first.
- 441 has no intentional molybdenum range and should not be assumed to match molybdenum-bearing grades in chloride pitting or crevice conditions.
- Ferritic forming texture, weld grain growth and lower low-temperature toughness can require different design rules from austenitic 304.
Quoted product forms
Quoted product forms for 441 Stainless Steel (UNS S43940)
We quote 441 Stainless Steel as coil / strip, sheet / plate, pipe / tube against the named product standard.
- Traceability: heat or lot identity plus the inspection document named in the RFQ (EN 10204 3.1 when that route supports it).
- Processing: decoiling, cutting, polishing, shearing and beveling as ordered.
- Next step: send product form, size and quantity; we quote the supply route.
Chemical Composition (wt%)
| C | Mn | Si | Cr | Ti | Nb | P | S |
|---|---|---|---|---|---|---|---|
| ≤0.030 | ≤1.00 | ≤1.00 | 17.5–18.5 | 0.10–0.60 | 3×C+0.30–1.00 | ≤0.040 | ≤0.015 |
Single values are maximums unless a range is shown. Balance: Fe. Per EN 10088-2, ASTM A240/A240M.
Mechanical Properties
| Yield strength Rp0.2 | ≥230 MPa |
|---|---|
| Tensile strength Rm | 430–630 MPa |
| Elongation A80 | ≥18% |
| Basis | EN 10088-2, cold-rolled |
Room-temperature minimum values are summarized for annealed flat product under EN 10088-2, ASTM A240/A240M unless a condition is named in the property label; product form and thickness can change the requirement.
Physical Properties & Structure
| Density | 7.7 g/cm³ |
|---|---|
| Magnetic response | Magnetic because the room-temperature matrix is ferritic. |
| Microstructure | Ferritic (dual-stabilized) |
Corrosion Resistance & Limits
- 441's chromium content supports oxidation and general corrosion performance above lower-chromium exhaust ferritics in some duties, but scale behavior still changes with metal temperature, gas chemistry, deposits and cycling.
- The ferritic matrix has a different chloride stress-corrosion response from austenitic 304, yet 441 can still pit, crevice corrode or suffer condensate attack. Weld condition, road salts, retained moisture and surface contamination require validation.
Fabrication & Heat Treatment
| Welding | Use a procedure qualified for stabilized ferritic sheet or tube, controlling heat input, interpass temperature, fit-up and shielding to limit grain coarsening and loss of joint toughness. Clean oxides according to the corrosion and appearance requirement. |
|---|---|
| Forming | 441 is suitable for many bent and roll-formed exhaust shapes, but ferritic anisotropy, springback and edge stretch need part trials. Deep draws and tight radii should be validated against coil direction, thickness and surface finish. |
| Machining | Sharp tooling, rigid support and controlled heat are important on thin formed or welded sections. Keep carbon-steel contamination away from cut edges and surfaces that will face hot condensate or exterior exposure. |
| Heat treatment | 441 is not hardened by conventional heat treatment. Any annealing or thermal processing after forming must follow the material and part specification because grain size, stabilization, oxide scale and distortion influence acceptance. |
Equivalent Grades
The closest international equivalents of 441 Stainless Steel are 1.4509 (X2CrTiNb18) in the EN system, 022Cr18NbTi in the GB system.
These are common corresponding designations, not unconditional substitutes. Verify chemistry, mechanical properties, product standard, delivery condition, dimensions and project approval before changing designation.
| System | Designation |
|---|---|
| UNS | S43940 |
| EN | 1.4509 (X2CrTiNb18) |
| GB | 022Cr18NbTi |
Ordering Checks for 441
- State EN 1.4509 or UNS S43940 with the governing product standard, form, dimensions, thickness, finish and delivery condition.
- Provide normal and peak metal temperature, gas chemistry, thermal cycles, vibration, condensate, road salts and exterior appearance criteria.
- Define forming direction, bend and draw severity, weld process, heat input, filler, shielding, fixtures and leak or fatigue test requirements.
- Specify inspection documentation and verify ordered chemistry, stabilization, mechanical properties, heat treatment, dimensions and heat traceability.
Reference Product Forms & Dimensional Ranges
Common reference product forms for 441 stainless steel: Coil / Strip, Sheet / Plate, Pipe / Tube.
| Finishes | 2B, 2D, bright annealed |
|---|---|
| Sheet / coil thickness | 0.4–3.0 mm |
| Common widths | 1000 / 1250 mm |
Common surface and delivery options
- No.1, 2B, BA or mechanically polished finish when supported by the product route
- Annealed and pickled, descaled or polished tube finish as specified
These published ranges are engineering references, not a live-stock or production-capability promise. Send the required product form, dimensions, condition and finish; we quote the matching supply route.
Browse related product hubs:Sheet & plate,Coil & strip,Pipe & tube,Bar & rod.
Typical Applications
- Exhaust manifolds and hot-end pipes
- Welded ornamental and structural tube
- Heat exchanger plates
- Solid-oxide fuel cell interconnects
- Selected exterior sheet and tube after finish and environment review
Frequently Asked Questions
Why is 441 stabilized with both titanium and niobium?
Titanium and niobium control interstitial elements and support stabilization, while their combined effect can benefit weld and elevated-temperature behavior. The chemistry does not make welding unrestricted: heat input, grain growth, filler, shielding, joint geometry and thermal-fatigue validation remain necessary.
441 vs 409L — when to upgrade?
441 has a higher chromium range and dual stabilization, so it is considered where a 409L component lacks oxidation, thermal-fatigue or appearance margin. Upgrade decisions need the measured metal temperature, cycle, condensate, geometry and current material route; fixed gas-temperature thresholds are not sufficient.
Is 441 a substitute for 304 in appearance parts?
Not as a direct substitution. A brushed 441 surface can meet some appearance requirements, but ferritic texture, magnetic response, forming anisotropy, weld practice, thermal expansion and corrosion behavior differ from 304. Approve samples and recalculate fabrication before changing grade.
Published by Tsingshan (Shandong) Iron & Steel Co., Ltd..Sources, update policy and technical limitations.
Quote request
Get a 441 Stainless Steel Quotation
Send the product, grade and quantity you already have. We will complete the specification and quote the supply route.