What is SUS316l stainless steel meaning?

SUS316L Stainless Steel – Meaning and Key Properties

1. Meaning of SUS316L

SUS: Abbreviation for "Stainless Steel" in the Japanese Industrial Standards (JIS), serving as a standard prefix for stainless steel grades in Japan.

316: Indicates an austenitic stainless steel primarily alloyed with Chromium (Cr), Nickel (Ni), and Molybdenum (Mo). It corresponds to AISI 316 in the U.S. and EN 1.4401 in Europe.

L (Low Carbon): Signifies a low carbon content (≤0.03%, compared to ≤0.08% in standard 316). The reduced carbon prevents carbide precipitation at weld joints or high temperatures, thereby improving resistance to intergranular corrosion.

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2. Chemical Composition of SUS316L (JIS G4303 Standard)

Element	C	Si	Mn	P	S	Cr	Ni	Mo
Content	≤0.03%	≤1.0%	≤2.0%	≤0.045%	≤0.03%	16–18%	10–14%	2.0–3.0%

Molybdenum (2–3%): Significantly improves corrosion resistance, especially against chloride-containing environments (e.g., seawater, salt solutions, chemical acids). Offers approximately three times the pitting and crevice corrosion resistance of 304 stainless steel.

Low Carbon (C ≤ 0.03%): Prevents formation of Cr₂₃C₆ carbides during welding or high-temperature service, effectively mitigating intergranular corrosion. Ideal for welded structures such as pressure vessels and piping.

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3. Mechanical Properties of SUS316L (at Room Temperature)

Property	Value
Tensile Strength	≥480 MPa
Yield Strength	≥175 MPa
Hardness (HB)	≤187
Operating Temperature	-196°C to 800°C

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4. Advantages of SUS316L Stainless Steel

Corrosion Resistance

Excellent resistance to medium-strength organic acids such as sulfuric, phosphoric, and acetic acids.

Outstanding performance in chloride-rich environments (e.g., marine heat exchangers, pool systems), significantly outperforming 304 stainless steel.

Passes intergranular corrosion test in 10% oxalic acid solution (per JIS G0571) with no signs of corrosion grooves-ideal for demanding welded structures.

Processability

Can be strengthened via cold working (e.g., cold drawing, cold rolling) while maintaining excellent weldability.

ER316L welding wire is recommended to avoid carbide precipitation in heat-affected zones.

Sanitary Qualities

Smooth surface resists scaling and contamination; complies with FDA, 3A, and other food-grade standards.

Commonly used in pharmaceutical manufacturing equipment and food storage tanks.

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5. Applications of SUS316L

Chemical & Petrochemical: Reactors, pressure vessels, pipelines for handling chloride or organic acid media.

Marine Engineering: Desalination systems, ship fittings-resistant to salt spray corrosion.

Food & Medical Industries: Pharmaceutical machinery, surgical instruments, infusion systems.

Architectural Applications: Coastal building facades, outdoor sculptures-superior weather resistance compared to 304.

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6.SUS316L Standards

Region	Grade & Standard
Japan (JIS):	SUS316L (JIS G4303, G4305)
USA (ASTM):	316L (ASTM A276, A479)
Europe (EN):	1.4404 (EN 10088-2)
China (GB):	022Cr17Ni12Mo2 (GB/T 20878)