If you need a stainless steel that resists corrosion in high-heat, chemical-rich, or marine environments—while avoiding the risk of intergranular corrosion—JIS SUS316L stainless steel is your solution. As the low-carbon version of SUS316, it adds extra protection against heat-induced cracking, making it a top choice for pharmaceutical, marine, and industrial projects. This guide covers everything you need to use it effectively.
1. Material Properties of JIS SUS316L Stainless Steel
JIS SUS316L stainless steel stands out for its balanced material properties, with two key advantages: molybdenum for corrosion resistance and low carbon content to prevent intergranular damage. Let’s break it down:
Alloy Composition
The “L” in SUS316L means “low carbon”—a critical tweak that sets it apart from standard SUS316. Here’s the exact mix:
| Element | Content Range | Role in Performance |
|---|---|---|
| Chromium | 16.0% – 18.0% | Forms a protective oxide layer (fights rust and pitting) |
| Nickel | 10.0% – 14.0% | Stabilizes the austenitic structure (boosts ductility and toughness) |
| Molybdenum | 2.0% – 3.0% | Enhances resistance to chlorides (seawater, chemicals) |
| Carbon | ≤0.03% | Prevents intergranular corrosion (critical for high-heat use) |
| Manganese | ≤2.0% | Improves workability during manufacturing (rolling, welding) |
Mechanical & Physical Properties
It balances strength and flexibility, making it suitable for diverse projects. Here’s how it performs:
| Property | Typical Value (Annealed) | Practical Benefit |
|---|---|---|
| Mechanical Strength (Tensile) | 485 MPa | Handles pressure (ideal for chemical pipes or marine shafts) |
| Yield Strength | 170 MPa | Resists bending (great for offshore brackets or pharmaceutical tanks) |
| Elongation | ≥40% | Bends without cracking (perfect for curved marine parts or sinks) |
| Hardness | ≤210 HB (Brinell) | Soft enough for machining, yet durable against scratches |
| Density | 8.0 g/cm³ | Slightly denser than SUS304 (adds stability for heavy-duty parts) |
| Thermal Conductivity | 16.2 W/m·K (at 100°C) | Transfers heat evenly (suitable for heat exchangers in chemical plants) |
| Electrical Conductivity | 1.3 x 10⁶ S/m | Lower than copper (good for parts needing electrical insulation) |
A pharmaceutical equipment maker in Japan uses SUS316L for vaccine mixing tanks. Its high elongation lets them form the tanks into custom shapes, while the low carbon content ensures no corrosion during high-temperature sterilization.
2. Applications of JIS SUS316L Stainless Steel
Thanks to its corrosion resistance and low carbon content, JIS SUS316L stainless steel is used in industries where purity and durability are non-negotiable. Here are its top applications:
- Marine Applications: Ship hulls, propeller shafts, and offshore platforms. A shipyard in South Korea builds deep-sea research vessels with SUS316L hulls—no rust after 7 years in saltwater.
- Pharmaceutical Equipment: Drug manufacturing tanks and sterile conveyors. It meets strict FDA and JIS Z 2801 standards (no metal leaching into drugs). A Swiss pharma company uses it for insulin production—passes monthly purity tests.
- Chemical Processing Plants: Pipes and reactors for acids (sulfuric, nitric) and solvents. A chemical firm in Germany uses SUS316L for hydrochloric acid pipes—no leaks or corrosion for 6 years.
- Food Processing Equipment: Seafood processing machines and saltwater-based cleaning systems. A fish cannery in Norway uses SUS316L for conveyor belts—resists saltwater and fish oils.
- Medical Devices: Surgical tools and implantable parts (e.g., orthopedic screws). A medical device maker in the U.S. uses it for scalpels—easy to sterilize and biocompatible.
- Sanitary Fittings: Hospital faucets and lab sinks. A Singapore hospital uses SUS316L for operating room sinks—no corrosion from daily bleach cleaning.
3. Manufacturing Processes for JIS SUS316L Stainless Steel
JIS SUS316L stainless steel is versatile to manufacture, though its low carbon content and molybdenum require minor adjustments. Here are the key manufacturing processes:
- Hot Rolling: Heated to 1100–1200°C and rolled into thick plates, bars, or pipe blanks. Used for large parts like marine shafts. A steel mill in China uses hot rolling for SUS316L bars—ensures uniform strength.
- Cold Rolling: Done at room temperature to make thin sheets (e.g., pharmaceutical tank liners). Improves surface smoothness—critical for sterile applications.
- Annealing: Heated to 1050–1150°C and quenched in water. Softens the steel after cold working (e.g., bending) and restores corrosion resistance. A fabricator anneals SUS316L sheets before forming lab sinks—prevents cracking.
- Pickling: Treated with nitric acid to remove scale (from rolling or welding). Enhances the oxide layer—key for marine parts. A shipyard pickles SUS316L hull plates before painting—ensures no rust under the coating.
- Machining: Drilled, milled, or turned with carbide tools (better than HSS for molybdenum-rich steel). Use coolant to avoid overheating. A machine shop uses carbide tools to make SUS316L valve parts—achieves tight tolerances.
- Forming: Deep drawing (for sinks) and extrusion (for pipes) are easy, thanks to its 40% elongation. A sink manufacturer deep-draws SUS316L into seamless marine sinks—no leaks.
4. Corrosion Resistance of JIS SUS316L Stainless Steel
The biggest advantage of JIS SUS316L stainless steel is its exceptional corrosion resistance—it outperforms most stainless steels in harsh conditions, especially with heat:
- Intergranular Corrosion Resistance: Low carbon (≤0.03%) prevents cracking in high heat (e.g., 600°C chemical reactors). A refinery tested SUS316 vs. SUS316L—SUS316 cracked in 4 months, while SUS316L stayed intact.
- Pitting Resistance: Molybdenum resists small holes in chlorides. Tests show it withstands 3.5% saltwater (seawater) at 80°C—SUS304 fails at 60°C.
- Crevice Corrosion: Performs well in tight spaces (e.g., bolted joints) if cleaned regularly. A marine engineer tested SUS316L in seawater-filled crevices—no corrosion after 24 months.
- Stress Corrosion Cracking (SCC): Resists SCC in chlorides and acids. A chemical plant uses SUS316L for pressure vessels—no cracking under 120 bar pressure.
- Surface Treatment: Passivation (nitric acid treatment) thickens the oxide layer. A lab passivates SUS316L equipment—extends its life by 5x.
It’s not invincible (avoid concentrated hydrochloric acid), but it’s the best choice for most heat and chemical-rich environments.
5. Welding JIS SUS316L Stainless Steel
JIS SUS316L stainless steel has excellent weldability, but you need to match the filler to its low carbon and molybdenum content. Here’s how to do it right:
- Welding Processes: TIG (Tungsten Inert Gas) is best for thin parts (e.g., lab pipes), while MIG (Metal Inert Gas) works for thicker sections (e.g., marine brackets). A welder in Australia uses TIG for SUS316L pharmaceutical pipes—creates leak-proof welds.
- Welding Rods: Use low-carbon, molybdenum-rich fillers like AWS ER316L. Avoid SUS304 or standard SUS316 fillers—they lack low carbon, leading to intergranular corrosion. A shipyard once used ER316 (high carbon)—the weld cracked in 6 months.
- Welding Gases: Use argon (for TIG) or argon-2% CO₂ (for MIG) to protect the weld from oxygen. Prevents oxidation and weak spots.
- Post-Weld Heat Treatment: Rarely needed (low carbon reduces stress), but annealing at 1050–1150°C removes residual stress for load-bearing parts. A structural fabricator anneals SUS316L welds for offshore platforms—ensures no cracking in waves.
- Welding Inspection: Use X-ray testing for critical parts (e.g., drug tanks). A quality team tests SUS316L welds—catches tiny defects before they cause leaks.
- Welding Safety: Wear a heat-resistant jacket and helmet—SUS316L produces intense sparks.
6. Standards and Specifications for JIS SUS316L Stainless Steel
To ensure quality, JIS SUS316L stainless steel follows strict global standards. Here’s what you need to know:
- JIS G4304: The Japanese Industrial Standard for hot-rolled stainless steel (covers SUS316L’s dimensions and composition).
- ASTM A240: The U.S. standard (ASTM A240 Type 316L is equivalent)—you can use them interchangeably.
- EN 10088: The European standard (EN 10088-2 X2CrNiMo17-12-2 is the equivalent grade).
- ISO Standards: ISO 15510 specifies its chemical composition and mechanical properties for global projects.
- Material Certification: Ask for a Mill Test Certificate (MTC) to verify low carbon (≤0.03%) and molybdenum (2.0–3.0%) content. A pharmaceutical client requires MTCs for all SUS316L parts—ensures compliance with drug safety rules.
- Quality Control: Manufacturers test for corrosion resistance (salt spray tests) and tensile strength. A steel supplier rejects batches with carbon over 0.03%—they won’t resist intergranular corrosion.
7. Comparison with Other Materials
How does JIS SUS316L stainless steel stack up against other common materials? Here’s a clear breakdown:
| Material | Key Advantage vs. SUS316L | Key Disadvantage vs. SUS316L | Best For |
|---|---|---|---|
| SUS304 | Lower cost (~25% cheaper) | Poor chloride/heat resistance | Indoor sinks, furniture |
| SUS316 | Slightly higher tensile strength (515 MPa vs. 485 MPa) | Prone to intergranular corrosion | Non-heated marine parts (e.g., railings) |
| Carbon Steel | Much cheaper (~50% lower) | No corrosion resistance | Indoor beams, non-exposed parts |
| Duplex Stainless Steel | Higher strength | Less ductile (harder to form) | High-pressure oil pipes |
| Titanium Alloys | Extreme corrosion resistance | Very expensive (~5x cost) | Deep-sea equipment, aerospace parts |
| Aluminum Alloys | Lighter (density 2.7 g/cm³) | Less strong (tensile 276 MPa) | Lightweight parts (e.g., bike frames) |
For high-heat, chemical, or marine projects, SUS316L offers the best balance of performance and cost—beating SUS316 in heat resistance and titanium in affordability.
Yigu Technology’s Perspective on JIS SUS316L Stainless Steel
At Yigu Technology, JIS SUS316L is our top pick for clients in pharmaceutical, marine, and chemical sectors. Its low carbon content solves the intergranular corrosion issue that plagues SUS316, while molybdenum ensures durability in saltwater/chemicals. We help clients optimize welding (using ER316L fillers) and manufacturing to maximize lifespan—whether it’s for sterile drug tanks or offshore platforms. While it costs more than SUS304, its 3x longer service life makes it a cost-effective long-term choice.
FAQ About JIS SUS316L Stainless Steel
- What’s the difference between SUS316 and SUS316L?
The main difference is carbon content: SUS316 has ≤0.08% carbon, while SUS316L has ≤0.03%. This makes SUS316L resistant to intergranular corrosion in high heat—critical for reactors or sterilization equipment. - Can JIS SUS316L be used for medical implants?
Yes! It’s biocompatible (no metal leaching) and easy to sterilize. Many orthopedic screws and surgical tools use SUS316L—meets ISO 10993 medical safety standards. - Is JIS SUS316L more expensive than SUS304?
Yes, it’s about 25–30% more expensive. But for harsh environments (seawater, high heat), it lasts 2–3x longer than SUS304—saving money on replacements and maintenance.
