Outokumpu Therma range
Stainless steels for high service temperatures
Key grades
Therma 253 MA
An austenitic stainless steel with excellent oxidation and creep resistance in cyclic conditions that is best employed in temperatures up to 1150°C/2100°F. There is a slight susceptibility to embrittlement during continuous operation between 600–850°C/1110–1560°F.
Therma 310S/4845
An austenitic product with very good oxidation resistance in general and good oxidation resistance in mildly cyclic conditions that is best employed in temperatures up to 1050°C/1920°F. There is a slight susceptibility to embrittlement during continuous operation between 600–900°C/1110–1652°F.
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Why Therma range
Why Outokumpu
• Outokumpu is a global leader in stainless steel, and innovator of the first stainless steels in the world.• A strong customer focus, sustainability, and technical excellence are at the heart of everything we do.
• As a customer you benefit from our strong R&D and technical support.
Why stainless steel
• The durability of stainless steel means that it is not only the best, but also the most economically sustainable choice for a wide range of applications.• All of our products are made from an average of 85% recycled material and are fully recyclable at the end of their lifecycles.
Outokumpu Therma stainless steel grades
Therma 253 MA
Description An austenitic stainless steel with excellent oxidation and creep resistance in cyclic conditions that is best employed in temperatures up to 1150°C/2100°F. There is a slight susceptibility to embrittlement during continuous operation between 600–850°C/1110–1560°F.
EN 1.4835
ASTM type -
ASTM UNS S30815
Microstructure Austenitic
Typical applications
- Oil industry equipment
- Conveyor belts
- Refractory anchors
- Expansion bellows
- Radiant tubes
- Rotary kilns
- Exhaust manifolds
- Power generation applications
- Cyclone dip tubes
- Impact separators
- Bell furnaces
- Muffle furnaces
- Automotive exhaust components
- Tube shields
- Heat treatment trays
- Dampers
- Recuperator tubes
- Large-scale bakery ovens
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechnanical properties, physical properties and fabrication
Typical chemical composition, % by mass
C 0.09
Cr 21.0
Ni 11.0
Mo -
N 0.17
Others Si, Ce
Therma 310S/4845
Description An austenitic product with very good oxidation resistance in general and good oxidation resistance in mildly cyclic conditions that is best employed in temperatures up to 1050°C/1920°F. There is a slight susceptibility to embrittlement during continuous operation between 600–900°C/1110–1652°F
EN 1.4845
ASTM type 310S
ASTM UNS S31800
Microstructure Austenitic
Typical applications
- Furnace equipment
- Oil industry equipment
- Heat treatment baskets
- Heat exchangers
- Steam boilers
- Thermowells
- Automotive components
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet
Typical chemical composition, % by mass
C 0.05
Cr 25.5
Ni 19.1
Mo -
N -
Others -
Therma 4713
Description A ferritic low-alloyed stainless steel best employed at 550–800°C/1020– 1470°F when you need higher mechanical loading compared to other ferritic grades. Offers good resistance against sulfur attack compared to nickel-alloyed grades.
EN 1.4713
ASTM type -
ASTM UNS -
Microstructure Ferritic
Typical applications
- Furnace equipment
- Air heaters
- Annealing boxes
- Conveyor belts
- Thermowells
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechnanical properties, physical properties and fabrication
Typical chemical composition, % by mass
C 0.06
Cr 6.5
Ni -
Mo -
N -
Others Al, Si
Therma 4724
Description A ferritic low-alloyed product with improved oxidation resistance in temperatures up to 850°C/1560°F.
EN 1.4724
ASTM type -
ASTM UNS -
Microstructure Ferritic
Typical applications
- Furnace equipment
- Thermal boiler components
- Grids
- Burner nozzles
- Conveyor belts
- Thermowells
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechnanical properties, physical properties and fabrication
Typical chemical composition, % by mass
C 0.07
Cr 12.5
Ni -
Mo -
N -
Others Al, Si
Therma 4742
Description A ferritic stainless steel with very good oxidation resistance in temperatures up to 1000°C/1830°F, but which begins to be subject to embrittlement at temperatures above 950°C/1740°F.
EN 1.4742
ASTM type -
ASTM UNS -
Microstructure Ferritic
Usage
- Grids
- Burner nozzles
- Conveyor belts
- Chains
- Machine parts
- Cement processing equipment
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechnanical properties, physical properties and fabrication
Typical chemical composition, % by mass
C 0.07
Cr 17.5
Ni -
Mo -
N -
Others Al, Si
Therma 304H/4948
Description An austenitic Core 304/4301 variant with improved high-temperature creep strength that is best employed in temperatures up to 750°C/1380°F. Offers good formability and weldability.
EN 1.4948
ASTM type 304H
ASTM UNS S30409
Microstructure Austenitic
Typical applications
- Tubes
- Pressure vessels
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechnanical properties, physical properties and fabrication
Typical chemical composition, % by mass
C 0.05
Cr 18.1
Ni 8.3
Mo -
N -
Others -
Therma 321H/4878
Description An austenitic heat resisting stainless steel with comparable wet corrosion resistance to Core 321/4541 that is best employed in temperatures up to 850°C/1560°F
EN 1.4878
ASTM type 321H
ASTM UNS -
Microstructure Austenitic
Typical applications
- Furnace equipment
- Case hardening boxes
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechnanical properties, physical properties and fabrication
Typical chemical composition, % by mass
C 0.05
Cr 17.3
Ni 9.1
Mo -
N -
Others Ti
Therma 347H
Description An austenitic heat resisting stainless steel with excellent long-term creep resistance at at 550–600°C/1020–1110°F and comparable wet corrosion resistance to Core 347/4550.
EN -
ASTM type 347H
ASTM UNS S34709
Microstructure Austenitic
Usage
- Oil refineries
- Fired heater tubes
- Boiler casings
- Pressure vessels
- Reactor vessels
- Welded tubes
- Fittings
- Stack liners
- Tanks for storing organic chemicals
- Furnace heating elements
- Tanks for thermal storage
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechanical properties, physical properties and fabrication.
Typical chemical composition, % by mass
C 0.05
Cr 17.5
Ni 9.5
Mo -
N -
Others Nb
Therma 4828
Description An austenitic heat resisting stainless steel with improved oxidation resistance in temperatures up to 1000°C/1830°F. There is a slight susceptibility to embrittlement during continuous operation atbetween 600–850°C/1110– 1560°F.
EN 1.4828
ASTM type -
ASTM UNS -
Microstructure Austenitic
Typical applcations
- Furnace equipment (especially supporting parts)
- Annealing and hardening boxes
- Air heaters
- Exhaust systems
- Automotive components such as turbochargers
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechanical properties, physical properties and fabrication.
Typical chemical composition, % by mass
C 0.05
Cr 19.3
Ni 11.2
Mo -
N -
Others Si
Therma 309S/4833
Description An austenitic stainless steel with improved oxidation resistance in temperatures up to 1000°C/1830°F. There is a slight susceptibility to embrittlement during continuous operation at 600–900°C/1110–1652°F.
EN 1.4833
ASTM type 309S
ASTM UNS S30908
Microstructure Austenitic
Usage
- Furnace equipment
- Annealing boxes
- Thermowells
- Baffle plates
- Pots for quenching salt
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechanical properties, physical properties and fabrication.
Typical chemical composition, % by mass
C 0.06
Cr 22.3
Ni 12.3
Mo -
N -
Others -
Therma 153 MA
Description An austenitic stainless steel with excellent oxidation and creep resistance in cyclic conditions that is best employed in temperatures up to 1050°C/1920°F. This product has an excellent resistance to embrittlement.
EN 1.4818
ASTM type -
ASTM UNS S30415
Microstructure Austenitic
Typical applications
- Recuperators
- Conveyor belts
- Expansion bellows
- Power generation applications
- Cyclone dip tubes
- Bell furnaces
- Muffle furnaces
- Automotive components
- Tube shields
- Heat treatment trays
- Dampers
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechanical properties, physical properties and fabrication.
Typical chemical composition, % by mass
C 0.05
Cr 18.5
Ni 9.1
Mo -
N 0.15
Others Si,Ce
Therma 314/4841
Description An austenitic heat resisting stainless steel with excellent oxidation resistance in temperatures up to 1150°C/2100°F. There is a high susceptibility to embrittlement during continuous operation at 600–900°C/1110–1652°F
EN 1.4841
ASTM type 314
ASTM UNS S31400
Microstructure Austenitic
Typical applications
- Furnace equipment
- Superheater suspensions
- Enameling grates and hardening boxes
- Valves and flanges
Product forms
Datasheet Download Therma range datasheet for more information on corrosion resistance, mechanical properties, physical properties and fabrication.
Typical chemical composition, % by mass
C 0.06
Cr 24.3
Ni 19.2
Mo -
N -
Others Si
Standards and approvals for Therma range
| EN 10028-7 | Flat products for pressure purposes – Stainless steels |
| EN 10088-1 | Stainless steels – Part 1: List of stainless steels |
| EN 10088-2 | Stainless steels – Corrosion resisting sheet/plate/strip for general and construction purposes |
| EN 10088-3 | Stainless steels – Corrosion resisting semi-finished products/bars/rods/wire/sections for general and construction purposes |
| EN 10088-4 | Stainless steel flat products, technical delivery conditions, steels for constructions |
| EN 10217-7 | Welded steel tubes for pressure purposes – Stainless steel tubes |
| EN 10296-2 | Welded circular steel tubes for mechanical and general engineering purposes - Stainless Steel tubes |
| ASTM A182 / ASME SA-182 | Forged or rolled alloy-steel pipe flanges, forged fittings etc. for high temperature service |
| ASTM A240 / ASME SA-240 | Heat-resisting Cr and Cr-Ni stainless steel plate/sheet/strip for pressure purposes |
| ASTM A276 | Stainless and heat-resisting steel bars/shapes |
| ASTM A479 / ASME SA-479 | Stainless steel bars for boilers and other pressure vessels |
| Eurocode 3 / EN 1993-1-4 | Design of steel structures – Part 1-4: General rules – Supplementary rules for stainless steels |
| ISO 15510 | Stainless steels – chemical composition |
The most commonly used international product standards are given in the table. For a list of standards by product, see steelfinder.outokumpu.com
