Seamless Stainless Steel TP316LN Tube
Distinguished by the strategic addition of Nitrogen (0.10–0.16%), our TP316LN tubing offers significantly higher yield strength than standard 316L while maintaining excellent ductility and non-magnetic characteristics even after cold working. These tubes are indispensable for mission-critical applications in high-pressure chemical reactors, nuclear engineering, and cryogenic processing. Through advanced cold-drawing and precise solution annealing, GZH ensures every tube maintains a stable austenitic microstructure and optimized resistance to sensitization and pitting.
“TP316LN offers a minimum yield strength of 205 MPa, which is higher than the 170 MPa of standard TP316L.”
What Is a Seamless Stainless Steel TP316LN Tube?
TP316LN Seamless Stainless Steel Tube is a high-performance, precision-engineered tube crafted from a single, solid billet of a low-carbon, nitrogen-enhanced austenitic stainless steel. Unlike welded tubes, it has no weld joint, ensuring superior structural integrity and reliability, especially under high-stress and corrosive conditions. The"316LN"designation refers to a specific grade that is a low-carbon ("L") and nitrogen-enhanced ("N") version of Stainless Steel 316. The nitrogen addition increases the alloy's strength and provides enhanced resistance to pitting and crevice corrosion, while the low carbon content minimizes the risk of sensitization and intergranular corrosion in the heat-affected zone after welding.
Key Features and Advantages
Seamless TP316LN Stainless Steel Tubes offer a unique combination of benefits that make them invaluable in demanding environments:
Enhanced Corrosion Resistance: The added nitrogen improves the alloy's resistance to pitting and crevice corrosion, particularly in chloride-containing environments.
Superior Strength: The nitrogen content significantly increases the alloy's tensile and yield strength, providing higher design stress values compared to standard 316L.
Excellent Weldability: The low carbon content makes it highly resistant to intergranular corrosion in the heat-affected zone after welding, eliminating the need for post-weld heat treatment.
High Pressure and Temperature Tolerance: The seamless construction and robust material allow the tube to safely handle high internal pressures and moderate temperatures.
Cryogenic Service: It maintains excellent toughness and mechanical properties at extremely low temperatures, making it suitable for cryogenic applications.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Stainless Steel 316LN.
Table 1: Chemical Composition of Stainless Steel 316LN
The composition of Stainless Steel 316LN is carefully balanced to achieve its superior strength and corrosion resistance.
| Cr | Ni | Mo | N | P | S | Mn | Si | C |
| 16.50 - 18.50 | 10.00−14.00 | 2.00−3.00 | 0.10 - 0.16 | ≤0.045 | ≤0.03 | ≤2.00 | ≤0.75 | ≤0.03 |
Table 2: Typical Mechanical Properties of Stainless Steel 316LN
Stainless Steel 316LN is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Property | Value (Annealed) |
| Tensile Strength | ≥ 585 MPa |
| Yield Strength | ≥ 290 MPa |
| Elongation | ≥ 35% |
| Hardness | ≤ 217 HBW |
| Brinell Hardness | ≤217 HB |
Table 3: Typical Physical Properties of Stainless Steel 316LN
These physical properties highlight the material's ability to perform reliably under a wide range of conditions.
| Property | Value |
| Density | 8.0 g/cm³ |
| Melting Point | 1370 - 1400 °C |
| Thermal Expansion | 16.0 µm/m·°C (20-100°C) |
| Thermal Conductivity | 16.3 W/m·K (20°C) |
| Modulus of Elasticity | 193 GPa |
| Electrical Resistivity | 0.74 x 10⁻⁶ Ω·m (20°C) |
Table 4: The Standard of Stainless Steel Seamless Tube Size Tolerance Size Chart :
| Standard | OD(D) | Tolerance（MM) | Thickness(S) | Tolerance(MM) | Length | Tolerance | |
| MM | Common | High | MM | MM | |||
| EN 10216-5 HFD | 30≤D≤219.1（D2) | ±1.0% or ±0.5mm, whicever is the greater(取较大者) | T1, T≤4 | ±15% or ±0.6mm, whicever is the greater(取较大者) | L≤6M | +5/0 | |
| T2 | ±12.5% or ±0.4mm, whicever is the greater(取较大者) | ||||||
| 219.1≤D≤610 (D1) | ±1.5% or ±0.75mm, whicever is the greater (取较大者) | T≤0.05D | +22.5%/-15% | 6 | +10/0 | ||
| T1, 0.05D | ±15% or ±0.6mm, whicever is the greater(取较大者) | ||||||
| T2, T>0.09D | ±12.5% or ±0.4mm, whicever is the greater(取较大者) | L>12 | +by agreement/0 | ||||
| EN 10216-5 CFD | D3(D≤219.1) | ±0.75% or ±0.3mm, whicever is the greater(取较大者) | T3 | ±10% or ±0.2mm, whicever is the greater(取较大者) | |||
| D4(D≤219.1) | ±0.5% or ±0.mm, whicever is the greater(取较大者) | T4 | ±7.5% or ±0.15mm, whicever is the greater(取较大者) | ||||
| ASTM A213 HFD | D≤100 | +0.4/-0.8 | D<100,S≤2.4 | +40%/0 | HFD, all size | +5.0/0 | |
| +0.4/-1.2 | D<100,2.4 | +35%/0 | |||||
| +0.4/-1.6 | D<100,3.8 | +33%/0 | |||||
| D<100,S>4.6 | +28%/0 | ||||||
| 100 | +0.4/-1.2 | D>100, 2.4 | +35%/0 | ||||
| 200 | +0.4/-1.6 | D>100,3.8 | +33%/0 | ||||
| D>100,S>4.6 | +28%/0 | ||||||
| ASTM A213 CFD | D<25 | ±0.10 | D≤38.1 | +20%/0 | CFD, D<50.8 | +3.0/0 | |
| 25≤D≤40 | ±0.15 | ||||||
| 40 | ±0.20 | ||||||
| 50≤D<65 | ±0.25 | ||||||
| 65≤D<75 | ±0.30 | D>38.1 | +22%/0 | CFD, D≥50.8 | +5.0/0 | ||
| 75≤D≤100 | ±0.38 | ||||||
| 100 | +0.38/-0.64 | ||||||
| 200 | +0.38/-1.14 | ||||||
| ASTM A269 | D≤13 | ±0.13 | D≤13 | ±15% | D<38 | +3.2/0 | |
| 13 | ±0.13 | 13 | ±10% | ||||
| 38≤D<89 | ±0.25 | D>38 | +4.8/0 | ||||
| 89≤D<140 | ±0.38 | ||||||
| 140≤D<203 | ±0.76 | ||||||
| 203≤D<305 | ±1.01 | ||||||
| 305≤D<356 | ±1.26 | ||||||
| ASTM A270 | D<25 | ±0.13 | For weld pipe all size | ±12.5% | +3.0/0 | ||
| 25-50 | ±0.20 | ||||||
| 50-75 | ±0.25 | ||||||
| 75-100 | ±0.38 | For CD SMLS pipe D≤38.1 | +20%/0 | ||||
| 100-140 | ±0.38 | +5.0/0 | |||||
| 140-200 | ±0.75 | For CD SMLS pipe D>38.1 | +22%/0 | ||||
| 200-300 | ±1.25 | ||||||
Common Applications
The combination of high strength and exceptional corrosion resistance of TP316LN Stainless Steel Seamless Tube makes them a preferred choice for:
Chemical and Petrochemical Processing: For heat exchangers, pressure vessels, and piping in corrosive environments.
Oil and Gas Industry: In components for offshore platforms and piping systems where strength and corrosion resistance are critical.
Pharmaceuticals: In the production of pharmaceutical goods where high purity and resistance to corrosive media are essential.
Cryogenic Applications: For pipes and components in liquid natural gas (LNG) and other low-temperature systems.
Manufacturing Process
The manufacturing of a Seamless Stainless Steel TP316LN Tube is a precise, multi-step process:
- Heating: A solid billet of Stainless Steel 316LN is heated to a high temperature.
- Piercing: A piercing mill pushes a mandrel through the center of the heated billet to form a hollow shell.
- Drawing and Sizing: The hollow shell is then rolled and drawn to reduce its diameter and wall thickness to the desired dimensions.
- Heat Treatment: The tube is solution annealed to achieve its specified metallurgical properties and to ensure optimal performance.
- Finishing: The tube is cut to length, straightened, and subjected to rigorous testing to ensure it meets the highest standards for performance and reliability. This meticulous process ensures that every seamless Stainless Steel 316LN tube is built to withstand the most extreme operating conditions.
