These are plain chromium stainless steels with varying chromium content between 12 and 18%, but with low carbon content.
Basic properties
- moderate to good corrosion resistance increasing with chromium content
- not hardenable by heat treatment and always used in the annealed condition magnetic
- weldability is poor
- formability not as good as the austenitics
Common uses
- computer floppy disk hubs (430)
- automotive trim (430)
- automotive exhausts (409)
- colliery equipment (3CR12)
- hot water tanks (444)
Common ferritic stainless grades and their applications
Common Name | UNS No | Forms Available* | Typical Compositions (%) | Typical Applications | ||||
|
|
| C | Cr | Mo | Ti | Other |
|
409 | S40900 | Sheet and Coil | 0.02 | 11.5 | - | 0.25 | - | Heat resistant steel, easily formed and welded. Mainly used for automotive exhausts or welded applications where superior performance to galvanised steel is required. |
446 | S44600 | Tube and Pipe | 0.08 | 26.0 | - | - | - | Used for severe heat resistant applications up to 1200oC. In recuperators, highly resistant to sulphidation and oil ash corrosion. |
430 | S43000 | Sheet and Coil, Plate and Bar | 0.06 | 17.0 | - | - | - | Interior architectural components, stove and automotive trim, dishwasher and clothes dryer liners. Fusion welds tend to be brittle. |
444 | S44400 | Sheet and Coil | 0.02 | 18.5 | 2.0 | 0.4 | - | Heat exchanger and hot water tanks, and in chloride-containing waters. Not prone to chloride stress corrosion - superior resistance to pitting, crevice and intergranular corrosion. Possesses excellent deep drawing properties. |
12% Cr Structural Steels | S41003 | Sheet and Coil, Welded Tube and Hollow Sections | 0.02 | 11.5 | - | - | - | Mildly corrosive environments where better life cycle cost is obtainable than with carbon or galvanised steel. Usually referred to by proprietary designations eg 3CR12 or 5CR12. |
* Compatible or equivalent grades also available in castings. | ||||||||