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:
Melting and casting the 316L MOD alloy into billets or ingots.
Hot rolling the billets/ingots into seamless or welded pipe/tube.
Solution annealing the pipe/tube to achieve the desired microstructure.
Pickling and passivation to remove surface oxides.
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.