SUH409L Stainless Steel Chemical Composition.pdf

When sourcing SUH409L stainless steel, many buyers search for a SUH409L Stainless Steel Chemical Composition PDF before placing an order. The reason is simple: the chemical composition directly determines corrosion resistance, weldability, heat resistance, and compliance with automotive and industrial standards.

For exhaust system manufacturers, tube mills, stamping factories, and distributors, verifying the material composition before production is one of the most effective ways to reduce quality risks.

Click to download SUH409L Stainless Steel.PDF

What  is SUH409L Stainless Steel?

SUH409L is an ultra-low-carbon, titanium-stabilized ferritic stainless steel defined by the JIS G 4312 standard (Heat-resisting steel plate, sheet, and strip). It is the Japanese industrial standard equivalent of AISI 409L and EN 1.4512 (X2CrTi12). It exhibits excellent resistance to oxide scale peeling at continuous operating temperatures up to 675°C (1247°F) and intermittent operating temperatures up to 815°C (1499°F).

 

What is the main difference between SUH409 and SUH409L?
The "L" stands for Low Carbon. SUH409L has a lower carbon content (typically ≤0.030%) compared to standard 409. This reduction in carbon significantly improves weldability and corrosion resistance in the heat-affected zone (HAZ) after welding, making it the preferred choice for automotive exhaust systems.

 

SUH409L Stainless Steel Equivalent Grades

China Digital Grade	China New Grade	China Old Grade	JIS (Japan)	ASTM (USA)
S11163	022Cr11Ti	-	SUH409L	S40920

UNS (USA)	SAE (USA)	DIN (Germany)	EN (Europe)	Other
409	-	1.4512	X2CrTi12	-

 

Chemical Composition (Mass Fraction, %)

Grade	C	Si	Mn	P	S	Cr	Ti
SUH409L	≤0.030	≤1.00	≤1.00	≤0.040	≤0.030	10.50−11.7010	6×C∼0.756

 

Mechanical Properties (at Room Temperature)

Property	Value (Typical/Min)
Tensile Strength (σbσb)	≥360 MPa
Yield Strength (σ0.2)	≥175 MPa
Elongation (δ5)	≥25%
Hardness (HBW)	≤170
Hardness (HRB)	≤80
Hardness (HV)	≤175

 

Physical Properties

Property	Metric Unit
Density	7.75 g/cm³
Melting Point	1480 - 1530 °C
Specific Heat	460 J/(kg·K) at 20°C
Thermal Conductivity	25.8 W/(m·K) at 100°C
Modulus of Elasticity	200 GPa
Electrical Resistivity	0.60 Ω⋅mm2/m

 

Heat Treatment of SUH409L Stainless Steel

SUH409L (JIS G 4312) is a titanium-stabilized, low-carbon ferritic stainless steel that cannot be hardened by heat treatment. The primary heat treatment process is annealing at temperatures between 790°C and 900°C, followed by air cooling, to achieve optimal softness, formability, and corrosion resistance.

 

Is SUH409L magnetic?

Yes. As a ferritic stainless steel, SUH409L is strongly magnetic in both annealed and cold-worked states. This differs fundamentally from austenitic stainless steels like 304 or 316, which are non-magnetic or only weakly magnetic.

 

What are the heat resistance limits of SUH409L?

Continuous service temperature: Up to 650°C.
Intermittent service temperature: Up to 815°C.
Within this temperature range, it maintains good resistance to oxidation and scale spalling.

Can SUH409L be welded? What precautions should be taken?

Yes, it is weldable, and its weldability is excellent among ferritic stainless steels.
Welding methods: TIG, MIG, and resistance welding are commonly used.
Filler metal: It is generally recommended to use matching filler wire (409L) or austenitic filler wire (such as 309L) to enhance toughness.
Precautions: Heat input should be controlled during welding to prevent excessive grain coarsening, which could lead to joint embrittlement.

 

SUH409L Stainless Steel Applications

Automotive exhaust systems: Mainstream materials for manufacturing exhaust pipes, catalytic converter housings, mufflers, exhaust manifolds, and tailpipes.
Industrial thermal equipment: Used for heat exchangers, industrial furnace components, and gas turbine silencers.
General engineering: Applied in agricultural equipment, vessels, and certain non-decorative architectural components.

 

Why Choose GNEE for SUH409L Stainless Steel?

 

Chinese Manufacturer of SUH409L Stainless steel plate and Coils

Extensive Stock: We maintain an inventory of over 5,000 tons of SUH409L 2D coils in standard thicknesses (0.5mm to 3.0mm) to meet urgent project requirements.
In-Stock Products: Shipped within 3–5 days.
Custom Production: Delivered within 15–25 days via prioritized scheduling.
Flexible MOQ: Small-batch trial orders supported prior to mass production to meet R&D and prototyping needs.
Testing: 100% PMI (Positive Material Identification) testing available upon request; EN 10204 3.1 material test certificates provided.

 

SUH409L Stainless steel plate and Coils specifications

Product Form	Type	Thickness (mm)	Width (mm)	Length (mm)
Cold Rolled Coil (CRC)	Coil	0.30 – 3.0	1000 / 1219 / 1250 / 1500	(In Continuous Coil)
Cold Rolled Sheet (CRS)	Sheet	0.30 – 3.0	1000 / 1219 / 1250 / 1500	2000 / 2438 / 3000 / 6000
Hot Rolled Coil (HRC)	Coil	3.0 – 12.0	1000 / 1219 / 1250 / 1500	(In Continuous Coil)
Hot Rolled Plate (HRP)	Plate	3.0 – 20.0	1250 / 1500 / 1800 / 2000	2000 / 3000 / 6000 / 8000
Slit Strip	Strip	0.30 – 5.0	10 – 600 (Custom)	(In Coil)

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Surface Finish Options

Since SUH409L is primarily used for functional heat resistance (exhaust systems), No.1 and 2B are the most common.

Finish Designation	Process Description	Typical Application
No.1	Hot rolled, annealed, and pickled (descaled).	Heavy-duty exhaust manifolds, industrial silencers.
2B	Cold rolled, heat treated, pickled, and skin-passed.	Standard automotive exhaust pipes, muffler shells.
2D	Cold rolled, heat treated, and pickled (dull finish).	Deep drawing parts where high lubricant retention is needed.
BA (Bright Annealed)	Cold rolled and bright heat treated in a controlled atmosphere.	Visible automotive trim or parts requiring a smooth surface.

Delivery Conditions & Supply Details

This table covers the physical condition of the steel upon delivery.

Feature	Specification Details
Edge Type	Mill Edge (untrimmed) or Slit Edge (precision cut).
Coil ID (Inner Diameter)	508mm (20") or 610mm (24").
Surface Protection	Paper Interleaved, PE Film, or Laser Film (on request).
Standard Compliance	JIS G4312, ASTM A240, EN 10088-2.
Hardness Condition	Annealed (Soft Condition).

 

Packaging and Shipping

Packaging: Each sheet or coil is wrapped in moisture-proof paper with a plastic film lining and secured with steel strapping. The exterior is protected by wooden pallets or wooden crates to ensure safety during international transport.
Marking: Each package is labeled with the heat number, grade, dimensions, and standard specifications.
Shipping Method: Sea freight (FCL/LCL), air freight, or express delivery, depending on customer requirements.

FAQ

What is the difference between SUH409L and 441 stainless steel?

SUH409L and 441 are both ferritic stainless steels primarily used in automotive exhaust systems, but 441 is a higher-grade alloy. It features significantly higher chromium content (approx. 18%) and dual-stabilization (titanium + niobium), giving it better high-temperature strength and corrosion resistance compared to the lower-cost, 11% chromium SUH409L.

SUH409L vs. 439 stainless steel: Which offers better high-temperature resistance?

439 stainless steel offers significantly better high-temperature resistance than SUH409L. While both are titanium-stabilized ferritic alloys commonly used in high-heat applications like automotive exhaust systems, 439's higher chromium content (17% - 18%) prevents oxidation at much higher operating temperatures compared to the lower chromium (10.5% - 11.7%) in SUH409L.