AISI 316 vs 316L Stainless Steel (UNS S31603)
Both AISI 316 vs 316L stainless steel are molybdenum (Mo) containing austenitic stainless steel grades. The main difference between 316 and 316L stainless steel is the level of carbon content, weldability, corrosion resistance and mechanical properties. SS316 has a 0.08% max carbon content while SS316L (UNS S31603) only has a maximum 0.03% carbon content.
Since SS 316L has a much lower carbon content than SS316, the welding of 316L stainless steel is better than SS 316. In addition, AISI 316 might lead to stress-corrosion cracking or dimensional instability in service after welding, so postweld heat treatment is required for stress relief to reduce intergranular corrosion or stress-assisted intergranular corrosion, while SS316L generally does not have these problems.
SS316L can be used in applications where annealing cannot be performed after welding and maximum corrosion resistance is required.
AISI 316 (UNS S31600) and 316L (UNS S31603) are US steel grades, SUS 316 and SUS 316L are Japanese stainless steel grades.
Because of the additional molybdenum in this steel, the overall performance of the steel is better than that of AISI 310 and AISI 304 stainless steel. SS316 also has good resistance to chloride attack and is therefore commonly used in the marine environment.
Material 316L meaning: “3” refers to 300 series austenitic chromium-nickel alloys, L is stand for “Low carbon”.
Difference Between SS316 and SS316L Chemical Composition
Difference between 316 and 316L stainless steel composition is summarized in the tables below.
|SS316 and SS316L Chemical Composition (%)|
|UNS||Grade||C, ≤||Si, ≤||Mn, ≤||P, ≤||S, ≤||Ni||Cr||Mo|
AISI 316L Stainless Steel Properties
ASTM AISI 316L stainless steel properties are listed in the tables below, including mechanical properties and physical properties.
SS316 vs SS316L Mechanical Properties
The tables below give AISI 316 vs 316L stainless steel mechanical properties such as yield strength, tensile strength, elongation and hardness in different product forms and conditions.
|SS316 vs SS316L Mechanical Properties|
|ASTM Type||AISI Type||Conditions||Tensile Strength, MPa(ksi), ≥||0.2% Yield Strength, MPa(ksi),≥||Elongation in 50 mm (2 in.), %, ≥||Reduction of Area, %, ≥||Brinell Hardness (HBW), ≤||Rockwell Hardness (HRBW), ≤||Product forms|
|ASTM A276/A276M||316||Annealed, Hot finished||515 (75)||205 (30)||40||50||–||–||Bars and Shapes|
|316L||485 (70)||170 (25)||40||50||–||–|
|316||Annealed, Cold finished, Dia.≤12.7 mm (0.5 in.)||620 (90)||310 (45)||30||40||–||–|
|316||Annealed, Cold finished, Dia>12.7 mm (0.5 in.)||515 (75)||205 (30)||30||40||–||–|
|316L||485 (70)||170 (25)||30||40||–||–|
|ASTM A580/A580M||316||Annealed||520 (75)||210 (30)||35||50||Wire|
|316L||485 (70)||170 (25)||35||50||–||–|
|316||Cold finished||620 (90)||310 (45)||30||40||–||–|
|ASTM A240/A240M||316||515 (75)||205 (30)||40||–||217||95||Plate, Sheet, and Strip|
|316L||485 (70)||170 (25)||40||–||217||95|
|ASTM A473/A473M||316||Annealed||515 (75)||205 (30)||40||50||–||–||Forgings|
|316L||450 (65)||170 (25)||40||50||–||–|
1 MPa = 1 N/mm2
ASTM SAE AISI 316L Physical Properties
The datasheet below gives SS 316L density, melting point and magnetic permeability.
|AISI 316L (UNS S31603) Physical Properties|
|Density, g/cm3 (lb/in.3)||8.03 (0.29)|
|Melting point, °C (°F)||1375-1400 (2500-2550)|
|Magnetic permeability||1.02 (Approximate)|
316L Heat Treatment
Annealing: The recommended annealing temperatures for 316L wrought steel is 1400 °C (1900 °F).
Stress Relieving: Stress relief is usually not required unless you know or suspect that the environment will cause stress corrosion.
On the basis of 316, many steel types were developed. For example, after adding a small amount of titanium (Ti), SS 316Ti was developed. 316N was developed after adding a small amount of nitrogen (N), SS 317L was developed from the addition of nickel (Ni) and molybdenum (Mo).
AISI 316L SS equivalent to European EN standards (German DIN, British BSI, French NF…), Japanese JIS standards, Chinese GB standards, ISO and more.
|AISI 316L equivalent grade|
|Standards||Type||Standards||Grade (Steel Number)||Standard||Grade (ISO Number)||Standard||Grade||Standards||Grade||Standard||Grade||Standard||Grade||Standard||Grade||Standard||Grade|
|EN 10088-1; EN 10088-2; EN 10088-3||X2CrNiMo17-12-2 (1.4404)||ISO 15510||X5CrNiMo17-12-2 (4404-316-03-I)||JIS G4303||SUS316L||GB/T 20878;|
022Cr17Ni12Mo2 (New name)
Tags: SS316 vs SS316L, 316 vs 316L stainless steel, difference between 316 and 316L