ASTM A312 UNS S31653 is a high-performance austenitic stainless steel that is commonly referred to as aisi 316ln stainless steel or 1.4406 stainless steel. ASTM A312 Gr TP 316LN pipe offers exceptional resistance to corrosion, extreme temperatures, and stress cracking, making it an ideal material for use in a variety of applications.
AISI 316LN Stainless Steel Material Properties
One of the key characteristics of ASTM A312 UNS S31653 welded pipe is its exceptional resistance to pitting and crevice corrosion. This is due to its high levels of molybdenum and nitrogen, which improve the material's ability to withstand aggressive chemical environments. As a result of this, the EN 1.4429 Stainless Steel material is commonly used in applications such as chemical processing, food and beverage production, and pharmaceutical manufacturing.
Another key benefit of utilizing 1.4429 stainless steel is its resistance to high temperatures. The material is able to maintain its strength and structural integrity at extreme temperatures, making it an ideal choice for use in high-temperature applications such as furnace components, heat exchangers, and exhaust systems. Additionally, alloy 316ln stainless steel has excellent creep and fatigue resistance, which helps to extend the service life of components and reduce maintenance costs.
ASTM A312 UNS S31653 seamless pipe is also highly resistant to stress corrosion cracking, which is a major concern in many harsh environments. This is due to its low levels of carbon, which prevent localized corrosion from forming. This makes it an ideal material for use in applications such as marine environments, pulp and paper processing, and oil and gas production.
ASME SA312 UNS S31653 Physical Properties:
- Density: 7.98 g/cm³
- Coefficient of Thermal Expansion: 16.5 x 10^-6 /°C (20-100°C)
- Thermal Conductivity: 14.6 W/(m·K) (100°C)
- Specific Heat Capacity: 500 J/(kg·K) (0-100°C)
- Electrical Resistivity: 0.75 µΩ·m
- Magnetic Permeability: 1.02
Applications of AISI 316LN Stainless Steel Pipes
1. Chemical Processing: Due to its corrosion resistance, AISI 316LN is widely used in the chemical industry for handling corrosive chemicals and acids.
2. Oil and Gas: The X2CrNiMoN17-13-3 steel's high temperature and corrosion resistance make it suitable for applications in oil and gas processing, including pipelines and equipment.
3. Pharmaceuticals: AISI 316LN welded pipe is utilized in pharmaceutical manufacturing due to its hygienic properties and resistance to corrosion in pharmaceutical processes.
4. Marine Industry: The steel's resistance to saltwater corrosion makes it a preferred choice for marine applications, such as shipbuilding and offshore structures.
316ln VS 316 and 316l
ASTM A312 Grade tp316ln stainless Chemical Composition
| Grade | AISI 316 (1.4401) | AISI 316L (1.4404) | AISI 316LN (1.4406) |
| Cr (Chromium) | 16.5 – 18.5 % | 16.5 – 18.5 % | 16.5 – 18.5 % |
| Ni (Nickel) | 10 - 13 % | 10 - 13 % | 10 – 12.5 % |
| Mn (Manganese) | ≤ 2 % | ≤ 2 % | ≤ 2 % |
| Mo (Molybdenum) | 2 – 2.5 % | 2 – 2.5 % | 2 – 2.5 % |
| Si (Silicon) | ≤ 1 % | ≤ 1 % | ≤ 1 % |
| N (Nitrogen) | 0.11% | 0.11% | 0.12-0.22 % |
| P (Phosphorus) | 0.05% | 0.05% | 0.05% |
| C (Carbon) | ≤ 0.07 % | ≤ 0.03 % | ≤ 0.03 % |
| S (Sulphur) | 0.03% | 0.02% | 0.02% |
Alloy 316LN Steel Mechanical Properties
| Grade | AISI 316 (1.4401) | AISI 316L (1.4404) | AISI 316LN (1.4406) |
|
Density |
8 g/cm³ |
8 g/cm³ |
8 g/cm³ |
|
Elastic modulus |
193 GPa |
193 GPa |
200 GPa |
|
Hardness, Brinell |
215 Max HB |
215 Max HB |
220 Max HB |
|
Tensile strength |
500 - 700 MPa |
520 - 680 MPa |
580-780 MPa |
|
Yield strength |
200 MPa |
220 MPa |
205 MPa |
|
Coefficient of thermal expansion |
1.59*10-5 1/K |
1.59*10-5 1/K |
|
|
Thermal conductivity |
16.3 W/(m·K) |
16.3 W/(m·K) |
15 W/(m·K) |
|
Melting point |
1400 °C |
1400 °C |
1400 °C |
First, 316LN contains a higher percentage of nitrogen than AISI 316 and 316L stainless steel. This makes 316LN more resistant to pitting and crevice corrosion, especially in chloride-rich environments like seawater. AISI 316LN also has a higher tensile strength than AISI 316 and 316L, thanks to the increased nitrogen content. This can make it a preferred choice in applications where strength is a primary concern.
DIN 1.4429 Material Production process
DIN 1.4406 stainless steel pipes complying with ASTM A312 undergo seamless or welded production processes. Seamless pipes are manufactured by extrusion or rotary piercing, while welded pipes are manufactured using fusion welding methods.
ASME SA 312 UNS S31653 Tube Welding
Alloy 316LN stainless steel is an easy-to-weld material. Common welding methods include SMAW (electric arc welding), TIG (argon arc welding), MIG (metal inert gas welding) and resistance welding.
Grade 316ln Stainless Steel Heat Treatment Process:
AISI 316LN Solution Annealing:
Temperature range: 1010°C - 1150°C (1850°F - 2100°F)
Keeping time: 30 minutes to 2 hours
Solution treatment helps eliminate areas sensitive to intergranular corrosion caused by welding and restores material uniformity.
Rapid cooling:
After solution treatment, the workpiece is rapidly cooled to room temperature, usually using water or air cooling.
Rapid cooling helps prevent intergranular precipitation and improves the material's corrosion resistance.
Hardness Testing:
Hardness testing is performed to ensure that the hardness of the solution treated material is within the appropriate range.
Stress Relief Heat Treatment:
For larger or thicker welded parts, a stress relief heat treatment may be considered, typically in the 550°C - 650°C (1020°F - 1200°F) range.
Keeping time: 2-4 hours
Cool Down:
Cool slowly to room temperature to avoid re-inducing residual stresses.
