General Properties
Alloy 310 (UNS S31000) is an austenitic stainless steel designed for high-temperature corrosion-resistant applications. Here are some key points about Alloy 310: Alloy 310 exhibits good resistance to oxidation up to 2010°F (1100°C) under mildly cyclic conditions. It can withstand elevated temperatures without significant oxidation.Sulfidation and carburizing resistance: Due to its high chromium and moderate nickel content, Alloy 310 is resistant to sulfidation and can be used in moderately carburizing atmospheres. However, more severe carburizing atmospheres typically require nickel alloys such as Alloy 330 (UNS N08330). Alloy 310 can be used in slightly oxidizing, nitriding, cementing, and thermal cycling applications. However, the maximum service temperature may need to be reduced in these applications compared to non-cycling conditions. It is also suitable for cryogenic applications due to its low magnetic permeability and toughness down to -450°F (-268°C).Sigma phase precipitation: When heated between 1202 – 1742°F (650 – 950°C), Alloy 310 is subject to sigma phase precipitation, which can reduce toughness and mechanical properties. Solution annealing treatment at 2012 – 2102°F (1100 – 1150°C) can help restore some degree of toughness.Variants:
Alloy 310S (UNS S31008) is the low carbon version of the alloy, chosen for ease of fabrication. Alloy 310H (UNS S31009) is a high carbon modification developed for enhanced creep resistance. In many cases, the grain size and carbon content of the plate can meet the requirements of both 310S and 310H.
Applications
- Cryogenic Components
- Food Processing
Furnaces – burners, doors, fans, piping and recuperators
Fluidized Bed Furnaces – coal combustors, grids, piping, wind boxes - Ore Processing/Steel Plants – smelter and steel melting equipment, continuous casting equipment
Petroleum Refining – catalytic recovery systems, flares, recuperators, tube hangers - Power Generation – coal gasifier internals, pulverized coal burners, tube hangers
- Sintering/Cement Plants – burners, burner shields, feeding and discharging systems, wind boxes
- Thermal Processing – annealing covers and boxes, burner grids, doors, fans, muffles and retorts, recuperators, walking beams
Standards
ASTM........A 240ASME........SA 240
AMS..........5521
Corrosion Resistance
Wet Corrosion
Alloy 310 is not specifically designed for service in wet corrosive environments. The high carbon content, which is added to enhance creep properties, can have a detrimental effect on its resistance to aqueous corrosion. The alloy may be prone to intergranular corrosion after long-term exposure at high temperatures.However, it's worth noting that Alloy 310, with its high chromium content of 25%, offers better corrosion resistance compared to many other heat-resistant alloys. The significant chromium content contributes to its overall corrosion resistance properties.While Alloy 310 may not be ideal for wet corrosive environments, it can still provide satisfactory performance in high-temperature applications where resistance to oxidation and scaling is crucial.
High Temperature Corrosion
The high chromium (25%) and silicon (0.6%) content of Alloy 310 make it more resistant to high temperature corrosion in most in-service environments. Operating temperatures are listed below.
Oxidizing conditions (max sulfur content – 2 g/m3)
1922°F (1050°C) continuous service
2012°F (1100°C) peak temperature
Oxidizing conditions (max sulfur greater than 2 g/m3)
1742°F (950°C) maximum temperature
Low oxygen atmosphere (max sulfur content – 2 g/m3)
1832°F (1000°C) maximum temperature
Nitriding or carburizing atmospheres
1562 – 1742°F (850 – 950°C) maximum
The alloy does not perform as well as Alloy 600 (UNS N06600) or Alloy 800 (UNS N08800) in reducing, nitriding or carburizing atmospheres, but it does outperform most heat resistant stainless steels in these conditions.
Typical Creep Properties
|
Temperature |
Creep Strain (MPa) |
Creep Rupture (MPa) |
|||||
|
°C |
°F |
1000 H |
10000 H |
100000 H |
1000 H |
10000 H |
|
|
600 |
1112 |
120 |
100 |
40 |
200 |
140 |
|
|
700 |
1292 |
50 |
35 |
20 |
80 |
45 |
|
|
800 |
1472 |
20 |
10 |
8 |
35 |
20 |
|
|
900 |
1652 |
10 |
6 |
3 |
15 |
10 |
|
|
1000 |
1832 |
5 |
3 |
1.5 |
9 |
4 |
|
Chemical Analysis
Weight % (all values are maximum unless a range is otherwise indicated)
|
Element |
310 |
310S |
310H |
|
Chromium |
24.0 min.-26.0 max. |
24.0 min.-26.0 max. |
24.0 min.-26.0 max. |
|
Nickel |
19.0 min.-22.0 max. |
19.0 min.-22.0 max. |
19.0 min.-22.0 max. |
|
Carbon |
0.25 |
0.08 |
0.04 min. - 0.10 max. |
|
Manganese |
2.00 |
2.00 |
2.00 |
|
Phosphorus |
0.045 |
0.045 |
0.045 |
|
Sulfer |
0.030 |
0.030 |
0.030 |
|
Silicon |
1.50 |
1.50 |
0.75 |
|
Iron |
Balance |
Balance |
Balance |
Physical Properties
Density
0.285 lbs/in37.89 g/cm3
Specific Heat
0.12 BTU/lb-°F (32 – 212°F)502 J/kg-°K (0 – 100°C)
Modulus of Elasticity
28.5 x 106 psi196 GPa
Thermal Conductivity 212°F (100°C)
8.0 BTU/hr/ft2/ft/°F10.8 W/m-°K
Melting Range
2470 – 2555°F1354 – 1402°C
Electrical Resistivity
30.7 Microhm-in at 68°C78.0 Microhm-cm at 20°C
Mechanical Properties
Typical Values at 68°F (20°C)
|
Yield Strength 0.2% Offset |
Ultimate Tensile Strength |
Elongation in 2 in. |
Hardness |
||
|
psi (min.) |
(MPa) |
psi (min.) |
(MPa) |
% (min.) |
(max.) |
|
35,000 |
245 |
80,000 |
550 |
45 |
217 Brinell |
Fabrication Data
Alloy 310 can be easily welded and processed by standard shop fabrication practices.
Hot Forming
Heat uniformly at 1742 – 2192°F (950 – 1200°C). After hot forming a final anneal at 1832 – 2101°F (1000 – 1150°C) followed by rapid quenching is recommended.
Cold Forming
The alloy is quite ductile and forms in a manner very similar to 316. Cold forming of pieces with long-term exposure to high temperatures is not recommended since the alloy is subject to carbide precipitation and sigma phase precipitants.
Welding
Alloy 310 can be readily welded by most standard processes including TIG, PLASMA, MIG, SMAW, SAW and FCAW.