Type 316/316L Stainless Steel is a molybdenum steel possessing improved resistance to pitting by solutions containing chlorides and other halides.
Alloy 316/316L is an austenitic alloy and similar to 304/304L is used in a wide range of applications. It is an important alloy when it comes to chloride environments and many other chemical process industries. The addition of Molybdenum significantly increases general corrosion resistance as compared to 304/304L and more importantly, increases the chloride pitting resistance.
316/316L has excellent forming and welding characteristics. Due to its superior chloride pitting resistance, it is commonly used in applications involving chlorides or halides. That property is also useful in marine environments.
It also has an excellent resistance to intergranular corrosion in as-welded condition. Dual grade becomes important if heavy gauge welding is performed. This is where intergranular corrosion comes into picture and having a lower carbon version makes it difficult for Chromium Carbide to precipitate in the 797 to 1580 degF (425 to 860 degC) range when the welding is going on for a long time due to the heavy gauge.
It has excellent creep and rupture strength at higher temperatures compared to 304/304L. Finally, it has excellent strength and toughness at cryogenic temperatures.
Alloy 316/316L is an austenitic alloy and similar to 304/304L is used in a wide range of applications. It is an important alloy when it comes to chloride environments and many other chemical process industries. The addition of Molybdenum significantly increases general corrosion resistance as compared to 304/304L and more importantly, increases the chloride pitting resistance.
316/316L has excellent forming and welding characteristics. Due to its superior chloride pitting resistance, it is commonly used in applications involving chlorides or halides. That property is also useful in marine environments.
It also has an excellent resistance to intergranular corrosion in as-welded condition. Dual grade becomes important if heavy gauge welding is performed. This is where intergranular corrosion comes into picture and having a lower carbon version makes it difficult for Chromium Carbide to precipitate in the 797 to 1580 degF (425 to 860 degC) range when the welding is going on for a long time due to the heavy gauge.
It has excellent creep and rupture strength at higher temperatures compared to 304/304L. Finally, it has excellent strength and toughness at cryogenic temperatures.
Very wide ranging. It is practically used almost everywhere:
In addition, it provides excellent elevated temperature tensile, creep and stress-rupture strengths.
Grade | 316 | 316L |
UNS Designation | S31600 | S31603 |
Carbon (C) Max. | 0.08 | 0.030* |
Manganese (Mn) Max. | 2.00 | 2.00 |
Phosphorous (P) Max. | 0.045 | 0.045 |
Sulphur (S) Max. | 0.030 | 0.030 |
Silicon (Si) Max. | 1.00 | 1.00 |
Chromium (Cr) | 16.0 – 18.0 | 16.0 – 18.0 |
Nickel (Ni) | 10.0 – 14.0 | 10.0 – 14.0 |
Molybdenum (Mo) | 2.0 – 3.0 | 2.0 – 3.0 |
Nitrogen (N) | — | — |
Iron (Fe) | Bal. | Bal. |
Other Elements | — | — |
The main constituents of 316 stainless steel - other than iron - are Chromium and Nickel. However, it is the addition of 2% Molybdenum that provides the increased corrosion resistance.
316 contains 16 - 18% Chromium (Cr). Chromium is the essential chemical in all stainless steel and it is that which forms the thin passive layer that makes the metal "stainless"
316 also contains 10-14% Nickel (Ni). This is added to make the Austenitic structure more stable at normal temperatures.
The nickel also improves high-temperature oxidation resistance makes the steel resistant to stress corrosion cracking.
Where the steel is to be stretched formed a lower percentage (8%) of nickel should be selected. If the steel is to be deep drawn a higher percentage is better (9% or more).
In addition a number of other chemicals may be present but these are expressed as maximum permited levels with the exception of the increased quantity of carbon required in 316H - i.e. a minimum of .04% and a maximum of 0.10%
Electrical Resistivity |
7.2e-005 ohm-cm |
7.2e-005 ohm-cm |
at 20°C (68°F); 1.16E-04 at 650°C (1200°F) |
Magnetic Permeability |
1.008 |
1.008 |
at RT |
Material | Form | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation % | Hardness HB |
---|---|---|---|---|---|
Alloy 316L | 316L Sheet AMS 5507 | 100 max | - | 45 | - |
Alloy 316 | 316 Sheet AMS 5524 | 75 min | 30 | 45 | 207 max |
Alloy | UNS Design -ation |
Spec. | Tensile Strength | Yield Strength | ||||||||||
psi | MPa | ksi | psi | MPa | ksi | Elongation in 2 inches (min.) % | Grain Size Req. | Max. Hardness | Modulus of Elasticity (x106 psi) | Mean Coefficient of Thermal Expansion (IN./IN./°F x 10-6) | Thermal Conductivity (BTU-in/ft2-h-°F) |
|||
316 | S31600 | A249, A312 | 75,000 | 515 | 75 | 30,000 | 205 | 30 | 35 | — | 90 Rb | 28.0 | 9.2 | 116 |
316L | S31603 | A270, A312 | 70,000 | 485 | 70 | 25,000 | 170 | 25 | — | — | 90 Rb | 28.0 | 9.2 | 116 |
316H | S31609 | — | — | — | — | — | — | — | — | 7 or coarser | — | — | — | — |
Alloy | UNS Designation | Werkstoff NR. | Specifications* |
316 | S31600 | 1.4401 | A269, A/SA249, A/SA312, A1016, A632, A/SA688 |
316L** | S31603 | 1.4404 | A269, A/SA249, A/SA312, A1016, A632, A/SA688 |
*Note: The specifications noted including ASTM, ASME, or other applicable authorities are correct at the time of publication. Other specifications may apply for use of these materials in different applications.
Tensile Requirements - Stainless Steel 316/316L
Tensile Strength (KSI): 70
Yield Strength (KSI): 25
KSI can be converted to MPA (Megapascals) by multiplying by 6.895.
Type 316L is the low carbon version of 316 stainless. With the addition of molybdenum, the steel is popular for use in severe corrosion environments due to the materials immunity from boundary carbide precipitation (sensitisation).
The material is widely used in heavy gauge welded components and weld annealing is only required where the material is for use in high stress environments. 316L has an extensive variety of uses especially in marine applications due to the materials high corrosion resistance.
Type 316H is a higher carbon variant of 316 making the steel more suitable for use in applications where elevated temperatures are present.
Stabilised Grade 316Ti offers similar qualities.
The increased carbon content delivers a greater tensile and yield strength. The austenitic structure of the material also gives this grade excellent toughness, even down to cryogenic temperatures.
304 Stainless is a low carbon (0.08% max) version of basic 18-8 also known as 302.
Type 316 is more resistant to atmospheric and other mild environments than Type 304.
310S Stainless Steel has excellent resistance to oxidation under constant temperatures to 2000°F.
317L is a molybdenum bearing austenitic chromium nickel steel similar to type 316, except the alloy content in 317L is somewhat higher.
Alloy 321 (UNS S32100) is a titanium stabilized austenitic stainless steel with good general corrosion resistance.
Type 410 is a martensitic stainless steel which is magnetic, resists corrosion in mild environents and has fairly good ductility.
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Duplex 2507 (UNS S32750) is a super duplex stainless steel with 25% chromium, 4% molybdenum..
Material to UNS S32760 is described as a super duplex stainless steel with a microstructure of 50:50 austenite and ferrite.
ASTM A269 / A269M Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASME SA 249 Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes.
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