409 1.4512 X6CrTi12 Ferritic Stainless Steel
1.4512 409 stainless steel is a Ferritic steel that offers good mechanical properties and high-temperature corrosion resistance. It contains 11% chromium which is the minimum amount for the formation of the passive surface film which gives stainless steels their corrosion resistance. It combines good elevated temperature corrosion resistance with medium strength, good formability, and overall cost.
Applications
409 is the perfect grade stainless steel to be used in automotive applications where visual appeal is not a top priority. For this reason and for its durability to gas corrosion, 409 is most commonly used in truck exhaust systems, agricultural equipment, and heat and gas turbine exhaust silencer
Grade specifications for 409 grade stainless steel
Grade | UNS No | Old British | Euronorm | Japanese JIS | ||
BS | En | No | Name | |||
409 | S40900 | 409S19 | – | 1.4512 | X6CrTi12 | SUH 409 |
Mechanical properties of grade 409 stainless steels
Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
Rockwell B (HR B) max | Brinell (HB) max | ||||
409 | 450 | 240 | 25 | 75 | 131 |
Smelting Option
1 EAF: Electric Arc Furnace
2 EAF+LF+VD: Refined-smelting and vacuum degassing
3 EAF+ESR: Electro Slag Remelting
4 EAF+PESR: protective atmosphere Electro Slag Remelting
5 VIM+PESR: Vacuum induction melting
Forming Option
1 Hot rolling process
2 Hot Forging: Electro-hydraulic; High-speed-hydraulic; Oil-hydraulic; Precision-forging
Heat-treatment Option
1 +A: Annealed (full/soft/spheroidizing)
2 +N: Normalized
3 +NT: Normalized and tempered
4 +QT: Quenched and tempered (water/oil)
5 +AT: Solution annealed
6 +P: Precipitation hardened
Suface Option
1 Black Surface
2 Grounded: Bright but rough ; Not precision
3 Machining for plate: Bright and precision; Little turning scar
4 Peeled/Turned: Bright and precision; Little turning scar
5 Polished: Very Bright and precision size; Not turning scar
Other Services
1 Cutting: Small pieces
2 CNC Machine: Produce as your drawing
3 Package: Bare/Nylon/Canvas/Wooden
4 Payment:T/T, L/C, O/A(request credit)
5 Transport:FOB/CFR/CIF/DDU/DDP (train/ship/Air)
Corrosion Resistance
Grade 409 stainless steels have excellent resistance to exhaust gas and atmospheric corrosion, superior to that of 410 martensitic grades with 12% chromium and 3CR12. However, the corrosion resistance is lower than that of grade 430 steels containing 17% chromium. The surface of grade 409 steels is liable to mild corrosion, which limits the usage of steels for decorative purposes.
Heat Resistance
Grade 409 stainless steels offer scaling resistance at temperatures up to 675°C during continuous operation, and up to 815°C under intermittent conditions. These temperatures pertain to specific service environments.
Heat Treatment
Annealing of grade 409 steels is carried out at temperatures ranging from 790 to 900°C, followed by air-cooling. Thermal treatment does not harden grade 409 steels.
Welding
Grade 409 steels must be pre-heated to temperatures of 150 to 260°C before welding. Although grade 430 and 409 filler rods or electrodes can be used during welding of grade 409 steels, grade 309 electrodes or filler rods are strongly recommended by AS 1554.6. Care should be taken to weld grade 409 steels with minimum heat, in order to mitigate grain growth.