Characteristics
Type 409 has the lowest chromium content of the 400 series stainless steels. It cannot be heat-treated and because of its lower chromium content, Type 409 has lower corrosion resistance than other 400 series alloys and is not suitable for high quality appearance applications. Typical applications include automobile mufflers, casket liners, trailer bodies and swimming pool fixtures.
409L stainless steel grade provides good resistance to corrosion, oxidation, and heat up to 1500°F. It is non-hardenable and non-stabilized. Given it is a non-stabilized ferritic stainless steel, it is less readily welded and may not be suitable for applications requiring extensive or critical weldments.
409L high temperature resistance, can achieve high efficiency of the engine and exhaust system, and reduce the thickness of the exhaust system, can reduce exhaust emissions.
409L low cost, good flexibility, high rate of finished material, easy to replace, belongs to the environmental protection of new products.
Chemical Analysis Weight %
(all values are maximum unless a range is otherwise indicated)
| Chromium | 10.5 min. - 11.7 max. | Phosphorus | 0.04 |
| Manganese | 1.0 | Sulfur | 0.02 |
| Silicon | 1.0 | Carbon | 0.03 |
| Iron | Balance |
Features
Applications
This stainless steel grade provides excellent protection against exhaust gas and atmospheric corrosion at elevated temperatures. These mechanical properties offer critical advantages in the automotive and agriculture industries. One disadvantage of this stainless steel sheet is its exterior finishing characteristics – it is not recommended for decorative applications or where appearance is prioritized (like exterior auto body paneling or appliance surfaces).
In addition to automotive exhaust systems (tailpipes, mufflers, converters), this stainless steel grade is frequently used in non-automotive exhaust systems, heat exchangers, silencers, power generation, fuel filters, agricultural spreaders, furnace components, and transformer casing.
FAQ
Yes. Ferritic stainless steels are magnetic.
Ferritic stainless steel is one of the stainless steel families along with martensitic, duplex, and austenitic which describe the microstructure of the steel. They contain higher chromium content than martensitic steels and contain small amounts of ferrite stabilizers (i.e. titanium). They are magnetic.
409 stainless steel melts between 2500°F and 2590°F.
The max Brinell hardness number for 409 stainless is 207.
