Type 316 and 316L Stainless Steel

Compare Two Types of Stainless Steel

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Alloys are often added to steel to increase desired properties. Marine grade stainless steel, called type 316, is resistant to certain types of interactions. There are a variety of different types of 316 stainless steel, including 316 L, F, N, H, and several others. Each is slightly different, and each is used for different purposes.

While similar to Type 304 both Type 316 and 316L exhibit better corrosion resistance and are stronger at elevated temperatures.

They are also both non-hardenable by heat treatment and can be readily formed and drawn.

Annealing 316 and 316L stainless steels requires heating to between 1900-2100°F (1038-1149°C) before rapidly quenching.

What Are the Qualities of Type 316 Steel?

Type 316 steel is an austenitic chromium-nickel stainless steel that contains between two and three percent molybdenum. The molybdenum content increases corrosion resistance, improves resistance to pitting in chloride ion solutions and increases strength at high temperatures.

Type 316 grade stainless steel is particularly effective in acidic environments. This grade of steel is effective in protecting against corrosion caused by sulfuric, hydrochloric, acetic, formic and tartaric acids, as well as acid sulfates and alkaline chlorides.

How Is Type 316 Steel Used?

Common uses for type 316 stainless steel include in the construction of exhaust manifolds, furnace parts, heat exchangers, jet engine parts, pharmaceutical and photographic equipment, valve and pump parts, chemical processing equipment, tanks, evaporators, as well as pulp, paper and textile processing equipment and any parts exposed to marine environments.

What Are the Qualities of Type 316L Steel?

Type 316L stainless steel is an extra-low carbon version of the 316 steel alloy. The lower carbon content in 316L minimizes deleterious carbide precipitation as a result of welding. Consequently, 316L is used when welding is required in order to ensure maximum corrosion resistance.

Physical Properties of Type 316 Steels

  • Density: 0.799g/cm3
  • Electrical resistivity: 74 microhm-cm (20C)
  • Specific Heat: 0.50 kJ/kg-K (0-100°C)
  • Thermal conductivity: 16.2 W/m-k (100°C)
  • Modulus of Elasticity (MPa): 193 x 103 in tension
  • Melting Range: 2500-2550°F (1371-1399°C)

Type 316 and 316L Stainless Steel Composition:

ElementType 316 (%)Type 316L (%)
Carbon0.08 max.0.03 max.
Manganese2.00 max.2.00 max.
Phosphorus0.045 max.0.045 max.
Sulfur0.03 max.0.03 max.
Silicon0.75 max.0.75 max.
Chromium16.00-18.0016.00-18.00
Nickel10.00-14.0010.00-14.00
Molybdenum2.00-3.002.00-3.00
Nitrogen0.10 max.0.10 max.
IronBalanceBalance

Source: AK Steel Product Data Sheet. 316/316L Stainless Steel