316L Stainless Steel
Austenitic Stainless Steel

316L Stainless Steel

Low Carbon Marine Grade • Superior Corrosion Resistance

316L is a low carbon variant of 316 stainless steel, offering superior corrosion resistance, excellent weldability, and prevention of carbide precipitation during welding. Widely used in marine, medical, chemical processing, and pharmaceutical applications where corrosion resistance is critical.

Marine Applications Medical Grade Chemical Processing Food Equipment

Quick Specifications

UNS Number: S31603
ASTM: A240, A276
EN: 1.4404
Density: 8.00 g/cm³
Melting Point: 1370-1400°C
Magnetic: No
485-690
Tensile Strength (MPa)
45%
Machinability Rating
170
Yield Strength (MPa)
40%
Elongation
79
Max Hardness (HRB)

Material Overview

316L stainless steel is an austenitic chromium-nickel stainless steel containing molybdenum. The "L" designation indicates low carbon content (0.03% max), which minimizes carbide precipitation during welding and provides improved corrosion resistance in the as-welded condition.

This grade is particularly valuable in applications where welding is required, as it eliminates the need for post-weld annealing in most situations. The molybdenum content (2-3%) provides enhanced resistance to pitting and crevice corrosion in chloride environments, making it ideal for marine applications.

316L exhibits excellent formability, weldability, and corrosion resistance. It maintains good mechanical properties at elevated temperatures up to approximately 425°C and retains excellent toughness at cryogenic temperatures down to absolute zero.

Chemical Composition

Element Minimum % Maximum %
Carbon (C) - 0.030
Chromium (Cr) 16.0 18.0
Nickel (Ni) 10.0 14.0
Molybdenum (Mo) 2.0 3.0
Manganese (Mn) - 2.0
Silicon (Si) - 0.75
Phosphorus (P) - 0.045
Sulfur (S) - 0.030
Nitrogen (N) - 0.10

Mechanical Properties

Tensile Strength (Ultimate)
485-690 MPa
(70,000-100,000 psi)
Yield Strength (0.2% offset)
170 MPa
(25,000 psi) min
Elongation
40%
in 50mm (minimum)
Hardness
79 HRB
Rockwell B (maximum)

Additional Properties

Modulus of Elasticity: 193 GPa
Shear Modulus: 86 GPa
Poisson's Ratio: 0.265
Thermal Conductivity: 16.3 W/m·K
Thermal Expansion: 15.9 µm/m·°C
Electrical Resistivity: 74 µΩ·cm

Common Applications

Marine & Offshore

Boat fittings, offshore platform components, subsea valve bodies, marine fasteners, propeller shafts, seawater piping systems, desalination equipment.

Medical & Pharmaceutical

Surgical instruments, implantable devices, medical device components, pharmaceutical processing equipment, sterilization equipment, cleanroom fixtures.

Chemical Processing

Chemical processing vessels, heat exchangers, piping systems for corrosive chemicals, pump components, valve bodies, evaporators, condensers.

Food & Beverage

Food processing equipment, brewery systems, dairy equipment, beverage dispensing systems, commercial kitchen equipment, storage tanks.

Industrial

Pulp and paper equipment, textile machinery, photographic equipment, architectural panels, coastal structures, pollution control equipment.

CNC Machining Guidelines

Machining Characteristics

316L has a machinability rating of approximately 45% (compared to free-cutting B1112 at 100%). Work hardening during machining can be challenging. Use sharp tools, positive rake angles, and adequate coolant flow.

Turning Parameters

Cutting Speed: 60-90 m/min
Feed Rate: 0.2-0.4 mm/rev
Depth of Cut: 1-3 mm

Milling Parameters

Cutting Speed: 50-80 m/min
Feed per Tooth: 0.1-0.2 mm
Depth of Cut: 2-4 mm

Recommendations:

  • Use carbide or coated carbide tools for best results
  • Maintain positive rake angles (10-15°) to reduce cutting forces
  • Use water-soluble coolants or synthetic cutting fluids
  • Avoid dwelling or allowing tool to rub on work surface
  • Use chip breakers to control stringy chips

Welding & Forming

Welding

316L is readily weldable by all standard fusion and resistance welding processes. The low carbon content minimizes carbide precipitation, eliminating the need for post-weld annealing in most cases.

Recommended Filler Metals:

  • • ER316L (for matching composition)
  • • ER309L (for dissimilar metals)
  • • E316L-16 (stick welding)

Forming

Excellent formability. Can be deep drawn, bent, and formed by standard methods. Work hardening occurs during cold forming but can be restored by annealing.

Annealing Temperature:

  • • Solution Annealing: 1040-1150°C
  • • Rapid cooling recommended
  • • Water quenching preferred

Material Standards

UNS Number
S31603
ASTM
A240, A249, A276, A312
ASME
SA-240, SA-249
EN Number
1.4404
DIN
X2CrNiMo17-12-2
JIS
SUS 316L

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