Alloy 316L (UNS S31603)

Description:

Alloy 316L is an austenitic stainless steel supplied in the hot worked and annealed condition. The addition of Mo provides the product with much improved corrosion resistance compared with Alloy 304, particularly with respect to pitting and crevice corrosion in chloride environments. Alloy 316L resists atmospheric corrosion, as well as, moderately oxidising and reducing environments. It also resists corrosion in polluted marine atmospheres. The alloy has excellent resistance to intergranular corrosion in the as-welded condition.

It also provides higher creep, stress-to-rupture and tensile strength at elevated temperatures than a basic Alloy 304. As a fully austenitic grade it possesses excellent toughness, even down to cryogenic temperatures. This low carbon version of Alloy 316 is immune from the sensitisation caused by the precipitation of carbides at grain boundaries when heated, resulting in its widespread use in larger section welded components. It is readily formed and machined, although its relative toughness means that better machining is generally achieved at lower speeds with heavier feeds.

 

 

Key Features:

  • Higher resistance to pitting corrosion and crevice corrosion in seawater than Alloy 304 stainless steel
  • Pitting Resistance Equivalent number (PREN) of 25 compared with 19 for Alloy 304
  • Excellent ductility and impact strength at both ambient and sub-zero temperatures
  • Low carbon version of Alloy 316 thereby immune from grain boundary sensitisation
  • Excellent forming and welding characteristics
  • Non-magnetic except after significant welding or cold working

Applications:

  • Process industry equipment in chemical containers, transport units, heat exchangers and organic & fatty acid production
  • Marine and shipbuilding piping, pumps, valves, fittings and marine architecture
  • Oil & Gas industry piping, valves, pumps, heat exchangers
  • Mining industry for woven screens

Chemical Composition:

Cr Ni Mo Co Nb (+Ta) Ti V W Cu C Mn N Si P S Fe Al
Min 16.50 10.00 2.00
Max 18.50 13.00 2.50 0.04 2.00 0.11 1.00 0.04 0.03 Bal

Mechanical Properties:

Bars up to and including 1 3/8” (35mm) diameter or section Bars greater than 1 3/8” (35mm) diameter or section
0.2% Proof Stress 205 N/mm2 29.7ksi 205 N/mm2 29.7ksi
Tensile Strength, min 515 N/mm2 74.75ksi 515 N/mm2 74.75ksi
Tensile strength, max 700 N/mm2 101.5ksi 700 N/mm2 101.5ksi
Elongation, 5.65√S0 and 4D 35% 20%
Reduction of Area 40% 40%
Hardness (Brinell) <270 <270
Impact Strength (Room Temp) Typically >88J Typically >88J

Notes:

1.         Testing shall be carried out in accordance with ASTM A370 or EN ISO  6892-1 (tensile), EN ISO 6506-1 (hardness)

2.         Minimum properties quoted (tested at room temperature in a longitudinal direction)

3.         Testing performed on each melt of material per heat treatment batch

Physical Properties:

Density (Kg/m3) 8000
Magnetic Permeability (20°C) <1.05
Young’s Modulus (kN/mm2) 193
Specific Electrical Resistance, 20°C (µΩ-m) 0.74
Mean coefficient of thermal expansion, 20-100°C (m/m/°C) 15.9 x 10-6
Specific Heat, 20°C (J/kg.K) 500
Thermal conductivity, 20°C (W/m.K) 16.3

Downloads

Datasheet - S-Alloy 316L

Datasheet - S-Alloy 316L