316L MOD Stainless Steel Pipe

316L MOD (modified) stainless steel is a variant of the standard 316L alloy that has slightly different chemical composition and properties. Here are the key details about 316L MOD stainless steel pipes:

Alloy Composition:

• Chromium: 16-18%
• Nickel: 10-14%
• Molybdenum: 2-3%
• Carbon: Maximum 0.030%
• Nitrogen: 0.10-0.16%

The main difference from standard 316L is the higher nitrogen content, which helps improve the strength and corrosion resistance of the alloy.

Mechanical Properties:

• Tensile Strength: 515-655 MPa (75-95 ksi)
• Yield Strength: 205-450 MPa (30-65 ksi)
• Elongation: 35-55%

The higher strength compared to standard 316L allows 316L MOD pipes to be used in applications requiring greater load-bearing capacity.

Chemical/Corrosion Properties:

• Excellent resistance to pitting, crevice, and stress corrosion cracking.
• Superior resistance to chloride-induced corrosion compared to 316L.

Physical Properties:

• Density: 8.0 g/cm3
• Coefficient of Thermal Expansion: 16 x 10^-6 per °C
• Thermal Conductivity: 16 W/m·K

Manufacturing Process: The manufacturing process for 316L MOD pipes is very similar to standard 316L pipes:

1. Melting and casting the 316L MOD alloy into billets or ingots.
2. Hot rolling the billets/ingots into seamless or welded pipe/tube.
3. Solution annealing the pipe/tube to achieve the desired microstructure.
4. Pickling and passivation to remove surface oxides.
5. Final sizing, straightening, and cutting to desired lengths.

Applications:

• Chemical processing equipment
• Pulp and paper industry
• Petrochemical and refining applications
• Offshore and marine environments
• Power generation systems

The enhanced strength and corrosion resistance of 316L MOD make it a preferred choice over standard 316L in applications where more demanding service conditions are encountered.