310 / 310S
1.4585
This grade, combing excellent high temperature properties with good ductility and weldability is designed for cyclic elevated temperature service. It resists oxidation in continuous service at temperatures up to 2100⁰F provided reducing sulphur gasses are not present. It is also used for intermittent service at temperatures up to 1900⁰F because it resists rescaling and has a low co-efficient of expansion. This factor reduces the tendency of the steel to warp in heat service.
Type 310S is used when the application environment involves moist corrodents in a temperature range lower than that which is normally considered “high temperature” service.
Corrosion resistance
Excellent resistance at normal temperatures and when in high temperature service exhibits good resistance to oxidation and carburizing atmospheres. Resists fuming nitric acid at room temperature and fused nitrates up to 800⁰F.
Heat resistance
Good resistance to oxidation in intermittent service in air at temperatures up to 1900⁰F and 2100⁰F in continuous service. Good resistance to thermal fatigue and cyclic heating. Widely used where sulphur dioxide gas is encountered at elevated temperatures. Continuous use in 800 – 1575⁰F range not recommended but often performs well in temperatures fluctuating above and below this range.
Heat treatment
Annealing – heat to 1900 – 2100⁰F and cool rapidly for maximum corrosion resistance. This treatment is also recommended to restore ductility after each 1000 hours of service at 1200 – 1900⁰F.
Welding
Good characteristics suited to all standard methods. Type 310S electrodes generally recommended for fusion welding.
Typical applications
- furnace parts
- carburizing boxes
- heat exchangers
- oil burner parts
- heat treatment baskets and jigs
- welding filler wire and electrodes
AISI analysis (%)
| Grade | C | Mn | P | S | Si | Cr | Ni |
|---|---|---|---|---|---|---|---|
| 310 | .25 max | 2.0 max | .045 max | .030 max | 1.5 max | 24.0 to 26.0 | 19.0 to 22.0 |
| 310S | .08 max | 2.0 max | .045 max | .030 max | 1.5 max | 24.0 to 26.0 | 19.0 to 22.0 |
Mechanical properties (annealed)
| Yield Strength .2% Offset (psi) | Ultimate Strength (psi) | Elongation in 2” (%) | Hardness (Rb) | Hardness (BHN) | Impact Charpy (ft. – lbs) | Elastic modulus (psi) |
|---|---|---|---|---|---|---|
| 45,000 | 95,000 | 45 | 85 | 170 | 110 | 29.0×10⁶ |
Other properties
| Creep Strength 1% Flow in 10,000 h at 1,000⁰F psi | Magnetic Permeability at 200 H-Annealed | Electrical Resistivity at 68⁰F (μΩ-cm) | Thermal Expansion 32⁰ – 212⁰F (In/In/⁰F×10‾⁶) | Thermal Conductivity (BTU./ft.₂/hr./⁰F/ft) |
|---|---|---|---|---|
| 17,500 | 1.01 | 78 | 8.0 | 8.0 (at 212⁰F) 10.8 (at 932⁰F) |