310 Stainless Steel Sheet: Specifications, Applications & Performance Advantages

What Is 310 Stainless Steel Sheet?

310 stainless steel sheet, also designated UNS S31008, EN 1.4845 and JIS SUS310S, is a fully austenitic chromium-nickel heat-resistant grade containing nominally 25% chromium and 20% nickel. The high chromium and silicon contents give the alloy exceptional resistance to oxidation and scaling at elevated temperatures, while the stable austenitic structure retains useful mechanical strength under cyclic thermal loading. Sheet and plate are normally supplied in the solution-annealed condition in thicknesses commonly ranging from 0.5 mm to 50 mm, with wider dimensions available to project-specific requirements.

Chemical Composition per ASTM A240

The composition of 310 sheet is controlled to the limits given in ASTM A240 for UNS S31008. Values are maximum percentages unless a range is shown.

Element	C	Mn	P	S	Si	Cr	Ni
310 (S31008)	0.08	2.00	0.045	0.030	1.50	24.0-26.0	19.0-22.0

What the alloying elements do

Chromium 24.0-26.0%: forms a protective, self-repairing oxide layer that resists scaling up to about 1035 C in continuous service and about 1150 C in intermittent service.

Nickel 19.0-22.0%: stabilises the austenitic structure, improving high-temperature strength, creep resistance and ductility.

Silicon up to 1.50%: further improves oxidation resistance in air and flue-gas atmospheres.

Mechanical Properties

Minimum mechanical properties for 310 sheet and plate are specified in ASTM A240: tensile strength 515 MPa (75 ksi), 0.2% offset yield strength 205 MPa (30 ksi) and elongation 40% in 2 in. Density is approximately 7.98 g/cm3. The alloy remains ductile after prolonged high-temperature exposure, and normal service within the recommended limits avoids the sigma-phase embrittlement problems seen in some lower-alloy heat-resistant grades.

Property	Minimum Value per ASTM A240
Tensile strength	515 MPa (75 ksi)
Yield strength 0.2% offset	205 MPa (30 ksi)
Elongation in 2 in	40%

High-Temperature Applications

310 sheet is used wherever components must withstand sustained heat and oxidising gases: furnace linings and muffles, radiant tubes, heat treatment baskets and trays, kiln furniture, boiler internals, reformer and cracking-furnace internals in petrochemical plants, and high-temperature ducts in power generation. It also performs acceptably in marine environments where salt-spray exposure is combined with heat; where immersed chloride service is expected, a molybdenum-bearing grade should be evaluated instead.

Fabrication and Storage

310 sheet has good formability and can be bent, stamped, deep drawn, cut and machined with conventional equipment, although allowances should be made for the higher springback of the austenitic structure. Welding is carried out with matching austenitic filler metal; low heat input and rapid cooling of the weld are recommended to minimise carbide precipitation. For storage, keep the material in a dry, ventilated area, protect it from direct contact with chlorides and corrosive chemicals, and leave protective film and interleaving in place to avoid surface contamination.

Frequently Asked Questions

Q1: What thicknesses of 310 stainless steel sheet are commonly available?

A1: Sheet and plate are commonly supplied in thicknesses from 0.5 mm to 50 mm; thinner strip and thicker custom plate can be produced to project requirements.

Q2: Why is 310 sheet used in marine engineering?

A2: Its high chromium content gives strong resistance to salt-spray corrosion and high-temperature erosion near seawater, so it is used for coastal furnace and exhaust components. For permanent seawater immersion, molybdenum-bearing grades such as 316L are more appropriate.

Q3: How does 310 resist oxidation at high temperature?

A3: Chromium and silicon form a dense, adherent oxide film on the surface at temperature. The film self-heals if damaged and effectively prevents further oxidation of the base metal up to roughly 1035 C continuous and 1150 C intermittent exposure.

Q4: Can 310 sheet be bent and stamped?

A4: Yes. The austenitic structure gives good formability for bending, stamping and cutting. Allow for increased springback and use adequate tool radii to avoid cracking on tight bends.

Q5: How should 310 sheet be stored?

A5: Store in a dry, ventilated indoor area, away from moisture, chlorides and corrosive chemicals. Keep protective film in place and, where practical, store on wooden or coated supports to prevent condensation and surface contamination.

Q6: Is 310 suitable for food or general corrosion service?

A6: 310 is a heat-resistant grade, not a general-purpose corrosion grade. For food, kitchen and general atmospheric service, 304 or 316 offers a better balance of cost and corrosion resistance.