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Materials of Construction - Metals - 316/316L SS
May 28, 2003
Introduction
Type 316/316L
stainless steel is a molybdenum beraing grade of steel. The presence of molybdenum
gves this stainless steel better overall corrosion resistance properties than types 301
and 304 stainless steel. Type 316 gives useful service at room temperature in
sulphuric acid of concentrations lower than 15% wt. and greater than 85% wt. It also
resist chloride attack and is often used in marine environments.
Type 316L has a
maximum carbon content of 0.03% wt. It is used in applications where it is not
possible to anneal after welding and where maximum corrosion resistance is required.
Chemical
Composition (wt% typical)
| |
316 |
316L |
| Nickel |
Ni |
10.0 - 14.0 |
10.0 - 14.0 |
| Chromium |
Cr |
16.0 - 18.0 |
16.0 - 18.0 |
| Manganese |
Mn |
2.0 max |
2.0 max |
| Iron |
Fe |
Balance |
Balance |
| Carbon |
C |
0.08 max |
0.03 max |
| Phosphorus |
P |
0.045 max |
0.045 max |
| Sulphur |
S |
0.030 max |
0.030 max |
| Silicon |
Si |
1.0 max |
1.0 max |
| Molybdenum |
Mo |
2.0 to 3.0 |
2.0 to 3.0 |
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Corrosion Resistance
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Designations
UNS S3_____
Specifications
| ASTM |
Tube and Pipe |
|
|
Pipe - Welded |
|
|
Pipe - Seamless |
|
|
Tube - Welded |
|
|
Tube - Seamless |
|
|
Bars and Shapes |
|
|
Forgings |
|
|
Forged Flanges and Fittings |
|
|
Plate and Sheet |
|
|
Strip |
|
|
Rod and Shapes |
|
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Physical
Properties
| Electrical
Resistivity |
68°F |
74 microhm-cm |
| Coefficient of Thermal Expansion |
0-100°C (32-212°F) |
8.9 E-6 in/in °F |
| Magnetic Permeability |
|
1.02 |
| Themal Conductivity |
100°C (212°F)
500°C (932°F) |
9.4 BTU/ft h °F
12.4 BTU/ft h °F |
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Mechanical Properties
| Ultimate Tensile Strength |
579 MPa (84,000
psi) |
| Elongation in 50.8 mm (2 in.) |
50% |
| Yield Strength (0.2% offset) |
290 MPa (42,000
psi) |
| Hardness |
80 Rb
149 BHN |
| Impact Charpy |
135 ft lbs |
| Modulus of Elasticity (Tension) |
193,052 MPa (28,000,000 psi) |
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Fabrication
Welding
Good characteristics suited to all standard methods. Use Type 316Cb,
316L or 309Cb filler rods or electrodes depending on application. Welded sections in
Type 316 require post-weld annealing for maximum corrosion resistance. This is not
required if Type 316L is used.
Heat Treatment
Heat to 1010°C to 1121°C (1850°F to 2050°F) and cool rapidly. Type
316 and 316L cannot be hardended by thermal treatment.
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