316L stainless steel is an austenitic stainless steel that belongs to the standard CrNiMo stainless steels, the “L” at 316L stainless steel grade stands for low carbon(≤0.030%), it is the low carbon version of 316, adding 2 ~ 3% of molybdenum element enhances its corrosion resistance. 316L is food grade and marine grade, also called SS 316L and AISi UNS S31603. 316L stainless steel has excellent intergranular corrosion resistance and can maintain good corrosion resistance in harsh environments such as humidity, high temperature and corrosive media. It has good welding performance and processing performance and can be easily processed into various shapes and sizes of products to meet a variety of needs.
316L stainless steel is the second most used Austenitic stainless steel after stainless steel 304 due to its excellent properties, the austenitic structure also gives 316L excellent toughness, even down to cryogenic temperatures, grade 316L has low carbon content for improved resistance against intergranular corrosion after welding, compared to chromium-nickel austenitic stainless steels, 316L stainless steel with molybdenum content added offers higher creep stress to rupture and tensile strength at elevated temperatures., The higher nickel and molybdenum content in this grade allows it to demonstrate better overall corrosion-resistant properties than 304, especially concerning pitting and crevice corrosion in chloride environments. It can be used in most conditions due to its excellent properties.
316L Stainless Steel Composition
The chemical composition of stainless steel 316L is generally composed of 16 to 18% chromium, 10 to 14% nickel content, 2 to 3% molybdenum, and a small percentage of carbon(≤0.030%), adding molybdenum to stainless steel 316L increases its corrosion resistance compared to other grades of stainless steel.
| Standard | Grade | C | Mn | P | s | Cr | Ni | Mo | N | Iron |
|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A240 | 316L | ≤0.030 | ≤2.00 | ≤0.045 | ≤0.030 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 | ≤0.10 | Bal. |
| EN 10088-2 | 1.4404 | ≤0.030 | ≤2.0 | ≤0.045 | ≤0.030 | 16.5-18.5 | 10.0-13.0 | 2.0-2.5 | ≤0.10 | Bal. |
Compared to 316, 316L, 1.4401, 1.4404, 1.4435 in chemical composition
| C | Mn | P | S | Si | Ni | Cr | Mo | N | |
|---|---|---|---|---|---|---|---|---|---|
| 316 | 0.08 | 2.00 | 0.045 | 0.030 | 1.0 | 11-14 | 16-18 | 2-3 | |
| 316L | 0.035 | 2.00 | 0.045 | 0.030 | 1.0 | 10-14 | 16-18 | 2-3 | |
| 1.4401 | 0.07 | 2.00 | 0.040 | 0.015 | 1.0 | 10-13 | 16.5-18.5 | 2-2.5 | 0.11 |
| 1.4404 | 0.03 | 2.00 | 0.040 | 0.015 | 1.0 | 10-13 | 16.5-18.5 | 2-2.5 | 0.11 |
| 1.4435 | 0.03 | 2.00 | 0.040 | 0.015 | 1.0 | 12.5-15 | 17-19 | 2.5-3 | 0.11 |
316L Stainless Steel Mechanical Properties
| Standard | Grade | Yield Point | Tensile Strength | Elongation | Hardness | Hardness |
|---|---|---|---|---|---|---|
| MPa | MPa | % | HRB | HB | ||
| ASTM A240 | 316L | ≥ 170 | ≥ 485 | ≥ 40 | ≤ 95 | ≤ 217 |
| EN 10088-2 | 1.4404 | ≥ 240 | 530-680 | ≥ 40 |
Compared To 316, 316L 1.4401, 1.4404, 1.4435
| Grade | Tensile Strength(Mpa) | Yield Point(Mpa) | Elongation(%) | Hardness (HRB) |
|---|---|---|---|---|
| 316 | 515 | 205 | 35 | 95 |
| 316L | 485 | 170 | 35 | 95 |
| 1.4401 | 510-710 | 205 | 40 | 95 |
| 1.4404 | 490-690 | 190 | 40 | 95 |
| 1.4435 | 490-690 | 190 | 40 | 95 |
316L Stainless Steel Equivalent
| AISI | UNS | DIN | EN | JIS | GB |
|---|---|---|---|---|---|
| 316L | S31603 | 1.4404 | X2CrNiMo17-12-2 | SUS316L | 022Cr17Ni12Mo2 |
316L Stainless Steel Physical Properties
| Physical Properties | Metric | Imperial |
|---|---|---|
| Density | 8.0 g/cm3 | 0.289 lb/in3 |
| Melting point | 1375-1400 °C | 2500-2550 °F |
| Specific heat capacity | 500 J/kg·K at 20 °C | 0.12 Btu/lb·°F at 68 °F |
| Electrical resistivity | 0.74 μΩ·m at 20 °C | 29.13 μΩ·in. at 68 °F |
| Magnetic permeability | 1.01 (Approximate) | – |
| Elastic modulus (Modulus of Elasticity) | 193 GPa | 28 x 103 ksi |
| Thermal conductivity | 14.0-15.9 W/m·K | 8.09-9.19 Btu/ft·h·°F |
Forms Available
Corrosion Resistance
316L/4404 has excellent corrosion resistance in solutions of many halogen-free organic and inorganic compounds over a wide temperature and concentration range.
- It is a better choice than 304 in a range of atmospheric environments and many corrosive media due to the increased chromium and molybdenum content.
- Resist pitting and crevice corrosion in warm chloride environments, and stress corrosion cracking above about 122°F (50°C).
- Considered resistant to potable water with up to about 1000mg/L chlorides at ambient temperatures, reducing to about 500mg/L at 140°F (60°C).
- Usually regarded as marine-grade stainless steel, but is not resistant to warm sea water.
Heat Resistance
With good oxidation resistance in intermittent service to 870 °C and in continuous service to 925 °C, Grade 316L stainless steel is more resistant to carbide precipitation.
Good oxidation resistance in intermittent service to 870 °C and in continuous service to 925 °C. Continuous use of 316 in the 425-860 °C range is not recommended if subsequent aqueous corrosion resistance is important. Grade 316L is more resistant to carbide precipitation and can be used in the above temperature range. Grade 316H has higher strength at elevated temperatures and is sometimes used for structural and pressure-containing applications at temperatures above about 500 °C.
Welding
Excellent weldability by all standard fusion methods, both with and without filler metals, heavy welded sections in grade 316 require post-weld annealing for maximum corrosion resistance, this is not required for grade 316L. 316L stainless steel in the welding process shows good performance, suitable for the use of a variety of welding methods, such as welding rod arc welding, argon arc welding, gas welding and submerged arc automatic welding. Selection of welding consumables, usually according to the composition principle, the choice of lower carbon content welding consumables, in order to enhance the welded joints resistance to weld thermal cracking and intergranular corrosion.
316L stainless steel welding process needs to pay attention to some special requirements. Due to the small thermal conductivity and large coefficient of linear expansion of 316L stainless steel, welding stress is easily generated during welding, which may lead to stress corrosion cracking. Therefore, in the selection of welding methods and materials, special attention needs to be paid to reduce welding stress and the formation of hot cracks.
Heat Treatment And Hardening
316L annealing temperature range is 1900 to 2100°F (1038 to 1149°C), cannot be hardened by heat treatment, It can be hardened by cold working.
Machining
316L stainless steel tends to work harden if machined too quickly. For this reason, low speeds and constant feed rates are recommended.
316L stainless steel is also easier to machine compared to 316 stainless steel due to its lower carbon content.
316 VS 316L Stainless Steel
316L is very similar to 316 in almost every aspect. They are both durable, corrosion-resistant and a good choice for high-stress applications, in practice, dual-certified grade 316/316L is often required. However, the “L” designation means 316L steel has less carbon than 316 steel, it is less susceptible to sensitization, a condition caused when carbon combines with chromium around the grain boundaries, depleting the grain boundary areas of chromium during the welding process, though it can be resisted via annealing.
Chemical Properties Comparison
| C | Mn | Si | P | S | Cr | Mo | Ni | N | |
|---|---|---|---|---|---|---|---|---|---|
| 316 (S31600) | 0.08 Max | 2.0 Max | 0.75 Max | 0.045 Max | 0.03 Max | Min: 16.0 Max: 18.0 | Min: 2.0 Max: 3.0 | Min: 10.0 Max: 14.0 | 0.10 Max |
| 316L (S31603) | 0.03 Max | 2.0 Max | 0.75 Max | 0.045 Max | 0.03 Max | Min: 16.0 Max: 18.0 | Min: 2.0 Max: 3.0 | Min: 10.0 Max: 14.0 | 0.10 Max |
Mechanical Properties Comparison:
| Grade | Tensile Strength Ksi (Min) | Yield Strength 0.2% Ksi (Min) | Elongation % | Hardness (Brinell) MAX | Hardness (Rockwell B) MAX |
|---|---|---|---|---|---|
| 316 (S31600) | 75 | 30 | 40 | 217 | 95 |
| 316L (S31603) | 70 | 25 | 40 | 217 | 95 |
Stainless Steel 316l vs 904l
Stainless steel 316L is a kind of molybdenum-containing stainless steel, whose chemical composition mainly consists of iron, chromium, nickel and other elements, in which the content of chromium is between 16%-18% and the content nickel is between 10%-14%. And 904L is a kind of ultra-low carbon stainless steel, its chemical composition includes lower content of iron, chromium, nickel and other elements, in which the content of chromium is between 18%-20%, and the content of nickel between 18%-20%. 904L stainless steel has greater corrosion and wear resistance due to its high content of alloying elements. 904L performs particularly well in chloride environments and strong acids such as concentrated sulphuric and phosphoric acid, while 316L stainless steel also has good corrosion resistance, it may not perform as well as 904L in some specific environments. There are also differences in manufacturing costs between 904L and 316L. Because 904L contains more rare metal elements, it is relatively more expensive to manufacture. This is one reason why 904L may not be as popular as 316L in some cost-sensitive applications.
316L Stainless Steel Plate, Bar, Tube
Stainless Steel Plate
Cold rolled 316L stainless steel plate (coil, strip, plate) can be offered in thickness ranging from 0.5 to 6.0mm, surfaces include 2B glossy, BA, 8K mirror, brushed, sandblasted, snowflake sand, stainless steel fingerprint-free plate decorative panels, coloured plate, titanium-plated plate, etched plate, oil-throwing hairline plate (HL, NO.4), 3D three-dimensional plate, sandblasted plate, embossed plate.
Hot rolled 316L stainless steel plate (coil, plate) can be offered in thickness ranging from 3-159mm, surface includes NO.1 (silver white, no lustre), brushed, sandblasted, snowflake sand, stainless steel embossed plate.
Stainless Steel Bar
The diameter of the 316L stainless steel bar usually ranges from 0.5mm to 300mm, and the specific specification size can be designed according to the demand. The common diameters are 1mm, 2mm, 3mm, 4mm, 5mm and so on. Different applications can be met through different diameters of bars. For example, smaller diameter bars can be used to make fine parts, while larger diameter bars can be used to make structural parts.
Regarding the length, 316L stainless steel rods are generally available in fixed lengths, usually 3 metres or 6 metres. Of course, other lengths of bar can be designed according to special needs.
In addition, 316L stainless steel bars can also be surface treated, such as bright, mirror, and frosted, depending on the application scenario. These surface treatments not only improve the aesthetics of the bar, but also increase its corrosion resistance and hardness.
Stainless Steel Tube
Shape: round tube, square tube, oval tube, hexagonal tube, trapezoidal tube and so on.
Use fluid tubes, heat exchanger tubes, sanitary tubes, decorative tubes, precision tubes, industrial tubes and so on.
Production method: seamless tube, welded tube, fine-rolled tube, cold-drawn tube and so on.
FAQ
Allergies to 316L stainless steel depend largely on an individual’s skin sensitivity. 316L stainless steel is hypoallergenic and generally friendlier to the skin, but not everyone is allergy-free. Characteristics of 316L stainless steel include corrosion resistance, smooth surface, hygiene and easy to maintain, hypoallergenic and very skin-friendly with little or no risk of allergies. This material is very machinable and non-magnetic. The nickel contained in 316L stainless steel may cause individuals to experience nickel allergic reactions, which may include itching, erythema, hives, oedema and rashes on the skin.
316L stainless steel jewellery is a good choice because it has excellent properties such as corrosion resistance, high-temperature resistance, and allergy resistance. 316 stainless steel is composed of chromium, nickel, molybdenum and other elements, has excellent corrosion resistance and oxidation resistance, widely used in food processing, medical equipment and chemical equipment and other fields. 316L stainless steel jewellery will not fade unless corrosion occurs under extreme conditions. Its main components include chromium, nickel and molybdenum, and these elements make 316 stainless steel have extremely high corrosion resistance and high-temperature resistance. In daily life, 316 stainless steel jewellery usually does not cause health problems. However, it should be noted that 316L stainless steel contains nickel, to which some people may be allergic. Therefore, people who are allergic to nickel should avoid using 316L stainless steel jewellery to prevent allergic skin reactions. In addition, in strong acid, alkali or highly chlorinated environments, 316 stainless steel may corrode, releasing metal ions, which may have an impact on the environment.
Due to the higher nickel and molybdenum content of 316L stainless steel, its cost is typically higher than that of 304. However, this additional cost may be considered worthwhile when considering corrosion resistance for long-term use. For those applications with stringent corrosion resistance requirements, it makes sense to choose 316L stainless steel. For those environments with higher cost requirements and lower corrosion resistance, 304 stainless steel may be a more economical choice.
The price of 316L stainless steel is higher than the price of 316 stainless steel. But the difference is not much. The reason for the price difference is that 316L stainless steel has a lower carbon content, which gives it better corrosion resistance and weldability. In addition, 316L stainless steel has superior mechanical and protective properties.
Related References
- ASTM A240/ASME SB240, Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
- ASTM A480, Standard Specification for General Requirements for Flat-Rolled Stainless and Heat-Resisting Steel Plate, Sheet, and Strip
- EN 10088-2, Stainless steels. Technical delivery conditions for sheet/plate and strip of corrosion-resisting steels for general purposes
- EN 10088-3, Stainless steels. Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion-resisting steels for general purposes
- EN 10088-4, Stainless steels. Technical delivery conditions for sheet/plate and strip of corrosion-resisting steels for construction purposes
- EN 10088-5, Stainless steels. Technical delivery conditions for bars, rods, wire, sections and bright products of corrosion-resisting steels for construction purposes
- ASTM A249, Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes
- ASTM A213, Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes
- ASTM A312, Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
- ASTM A276, Standard Specification for Stainless Steel Bars and Shape