Description
SS 409L Plates / Sheets
SS 409L Plates is a kind of stable version of 409, composed with proper chromium, low composition of carbon and nitrogen and adjunction of titanium, all composition appropriate make Grade 409L have some properties, like corrosion resistance, weldability and formability. Due to the lower chromium, SS 409L was another low cost option for corrosion resistant stainless steel.
It has a good combination of heat resistance and corrosion resistance, can be ideal for non- or lightly corrosive environments or applications. It has excellent oxidation resistance in high temperatures and good welding performance, which can be used for automotive exhaust pipes or oil equipment.
It is also known as UNS S40903 / EN 1.4512 .
409L Chemical Composition of 1.4512 / UNS S40903 :
| Elements | Min. | Max. |
| C | – | 0.03 |
| Si | – | 1.00 |
| Mn | – | 1.00 |
| P | – | 0.040 |
| S | – | 0.020 |
| Ni | – | 0.50 |
| Cr | 10.50 | 11.70 |
| Ti | 6 x (C+N) | 0.50 |
Applications of SS 409L:
409L steel is used in automotive exhaust systems
Heat exchangers
Catalytic converter systems
Culverts
Home heating systems
Automotive thermostats
Fuel filters
Key properties of 409L stainless steel
Corrosion resistance: It exhibits good resistance in natural atmospheres and moderately corrosive media. It is roughly 250 times more resistant to atmospheric corrosion than mild steel.
Heat resistance: It offers good heat resistance, withstanding temperatures up to approximately 800°C for continuous operation. Some sources suggest it can be used up to 1140°C in continuous service, provided reducing sulfur gases aren’t present.
Weldability: It has excellent weldability, comparable to carbon steel, and can be easily welded using standard commercial procedures. The addition of titanium helps prevent hardening during welding.
Formability and Ductility: It possesses good formability and ductility, similar to low alloy steels. This makes it suitable for forming into various shapes and components.
Low Cost: It’s considered a cost-effective option among corrosion-resistant stainless steels.
Typical applications of 409L stainless steel
409L stainless steel finds wide application in industries like automotive, manufacturing, and industrial equipment.
Specific applications include:
Automotive exhaust systems: Manifolds, exhaust pipes, catalytic converters, mufflers, and tailpipes.
Heat exchangers: Due to its excellent thermal conductivity and low thermal expansion coefficient, it’s well-suited for high-temperature applications like heat exchangers.
Home heating systems and automotive thermostats:
Electrical transformer cases and fuel filters:
Farm equipment components:
Culverts:




