Grade dossier
314 Stainless Steel for Oxidizing High-Temperature Service
A silicon-alloyed 25Cr-20Ni grade selected for strong oxidation resistance in high-temperature equipment, while creep, atmosphere and embrittlement risks remain design-specific.
Identity before substitution
Define the grade, product and condition together
A familiar grade name is not a complete purchase specification. Product form, controlling standard, dimensions, condition, finish, certification and service environment determine whether the delivered material is suitable.
Composition control
ASTM A240/A240M flat-product chemistry
Limits are not heat analysis targets
The table summarizes grade limits commonly used for plate, sheet and strip. Pipe, tube, bar, forgings and cast products can be governed by different specifications. Always place the product standard and edition on the purchase order.
| C | 0.25 max |
|---|---|
| Mn | 2.00 max |
| Si | 1.50-3.00 |
| P | 0.045 max |
| S | 0.030 max |
| Cr | 23.00-26.00 |
| Ni | 19.00-22.00 |
Properties with context
Minimums, typical indicators and delivered condition
Specified annealed flat-product values
| Tensile strength | 515 MPa min reference |
|---|---|
| 0.2% yield strength | 205 MPa min reference |
| Elongation | 40% min reference |
| Condition | Solution-annealed wrought product |
Selection indicators
| Density | about 7.8 g/cm3 |
|---|---|
| Producer air-temperature guidance | up to about 1150°C / 2100°F; not a design allowable |
| Silicon role | Supports protective oxide behavior |
| Important caution | Embrittlement risk during prolonged 600-900°C exposure |
Values depend on product form, thickness, test orientation, condition and governing edition. Use the mill test certificate and the purchase specification for acceptance, not a web table alone.
Selection boundary
Where 314 belongs and where to escalate
Grade selection is an environmental decision, not a popularity contest. Review the complete medium, temperature, geometry, fabrication, cleaning and inspection requirements.
Good reasons to evaluate it
Furnace equipment and enameling grates
Superheater suspensions and hardening boxes
High-temperature valves and flanges
Oxidizing service after detailed atmosphere review
Reasons to stop and review
Using air-oxidation guidance in carburizing or sulfurous gas
Ignoring prolonged intermediate-temperature embrittlement
Using room-temperature values for creep design
Substituting 310S without weld and code review
Fabrication route
Protect properties through cutting, forming and welding
Confirm availability and product standard before design freeze.
Use temperature-dependent creep and allowable-stress data.
Review weld filler and hot-cracking controls for silicon-rich chemistry.
Account for thermal expansion and shutdown conditions.
Supply definition
Product form changes the applicable requirements
Do not send an RFQ that names only the grade. State form, governing standard, dimensions, tolerances, finish, edge or end condition, quantity, certification and inspection.
Cold-rolled coil, strip and sheet
Hot-rolled coil, strip and plate
Quarto plate
Precision strip and fabricated furnace components
Certificate checkpoint
Request heat identity, chemical analysis, mechanical results and compliance to the exact product specification. Add PMI, corrosion testing or supplementary examination only when the application requires it.
Interactive selection check
Test 314 against the controlling question
Procurement FAQ
Questions to close before placing the order
Is 314 stainless steel magnetic?
Magnetic response depends on microstructure and delivered condition.
Can 314 replace another grade?
Only after checking the governing standard, composition, mechanical properties, corrosion exposure, fabrication route and certification. A commercial name is not a substitution approval.
Does the table apply to every product form?
Not automatically. The values shown use flat-product requirements as a reference. Other forms can use different product standards, dimensions and tests.
What should a 314 RFQ include?
Product form, standard and edition, UNS or EN designation, dimensions, tolerances, finish, quantity, service, fabrication, certificate and inspection requirements.
Sources, scope and RFQ
Use traceable grade data, then specify the actual product
ASTM A959 composition for wrought UNS S31400
Outokumpu Therma 314/4841 official datasheet
EN 10095 heat-resisting steel identity and air-temperature guidance
Applicable product standard and design code for the ordered form