Description
Stainless Steel 310, SUS310, SUS310S, UNS S31008, 1.4840, 1.4845
uns s31008 Chemical composition
Fe, <0.25% C, 24-26% Cr, 19-22% Ni, <2% Mn, <1.5% Si, <0.45% P, <0.3% S
SuS310, combining excellent high temperature properties with good ductility and weldability, is designed for high temperature service. It resists oxidation in continuous service at temperatures up to 1150°C provided reducing sulphur gases are not present. It is also used for intermittent service at temperatures up to 1040°C.
SUS310S (UNS S31008) is used when the application environment involves moist corrodents in a temperature range lower than that which is normally considered “high temperature” service. The lower carbon content of 310S does reduce its high temperature strength compared to SUS310.
Like other austenitic grades these have excellent toughness, even down to cryogenic temperatures, although other grades are normally used in this environment.
Chemicial Composition of Stainless Steel 310/310S
Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | |
SS310 | min.
max. |
–
0.25 |
–
2.00 |
–
1.50 |
–
0.045 |
–
0.030 |
24.0
26.0 |
– | 19.0
22.0 |
– |
SS310S | min.
max. |
–
0.08 |
–
2.00 |
–
1.50 |
–
0.045 |
–
0.030 |
24.0
26.0 |
– | 19.0
22.0 |
– |
Mechanical Properties for SUS310 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 |
||||
SS 310 | 515 | 205 | 40 | 95 | 217 |
SS 310S | 515 | 205 | 40 | 95 | 217 |
Comparison grade difference between 310 and 310S
Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
BS | En | No | Name | ||||
SS310 | S31000 | 310S24 | – | 1.4840 | X15CrNi25-20 | – | SUH 310 |
SS310S | S31008 | 310S16 | – | 1.4845 | X8CrNi25-21 | 2361 | SUS 310S |
These comparisons are approximate only. The list is intended as a comparison of functionally similar materials not as a schedule of contractual equivalents. If exact equivalents are needed original specifications must be consulted.
Alternative grades to aisi 310 stainless steels are given .
Grade | Why it might be chosen instead of SS310 |
3CR12 | Heat resistance is needed, but only to about 600°C. |
SS304H | Heat resistance is needed, but only to about 800°C. |
SS321 | Heat resistance is needed, but only to about 900°C. Subsequent aqueous corrosion resistance also required. |
253MA (2111HTR) | A slightly higher temperature resistance is needed than can be provided by 310. Better resistance to reducing sulphide atmosphere needed. Higher immunity from sigma phase embrittlement is required. |
Heat Resistance of stainless steel
Good resistance to oxidation in intermittent service in air at temperatures up to 1040°C and 1150°C 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 425-860°C range not recommended due to carbide precipitation, if subsequent aqueous corrosion resistance is needed, but often performs well in temperatures fluctuating above and below this range.
SUS310 is generally used at temperatures starting from about 800 or 900°C – above the temperatures at which SS304H and SS321 are effective.
Heat Treatment Solution Treatment (Annealing) – heat to 1040-1150°C and cool rapidly for maximum corrosion resistance. This treatment is also recommended to restore ductility after each 1000 hours of service above 650°C, due to long term precipitation of brittle sigma phase.
Applications include:
- Furnace parts
- Oil burner parts
- Carburising boxes
- Heat Treatment baskets and jigs
- Heat Exchangers
- Welding filler wire and electrodes