Typical Applications for 316 Stainless Steel

Brewing and dairy equipment, evaporators, drums, barrels, heat exchangers, chemical and food processing, water treatment plant, chemical processing equipment, architectural and boat fittings exposed to marine and polluted atmospheres are typical uses for grade 316 stainless steel.

Corrosion Resistance

316 stainless steel has excellent corrosion resistance in many environments. It gives good service in atmospheric conditions, resisting most environments and is often used in marine conditions, or where industrial pollution is heavy. Best appearance is maintained where the design allows even rain washing of the surface, or where dirt deposits are occasionally washed off the steel.

Grade 316 also has given excellent service in potable water. Pitting and crevice corrosion may occur in waters with higher chloride content, and 2000 ppm is accepted as the upper limit. The higher molybdenum content of 316 make it significantly more corrosion resistant than grade 304.

316 stainless steel can be used with seawater, provided precautions are taken to avoid crevice corrosion developing under sediments, precipitation and biofouling, and at designed-in crevices.

Grade 316, and grade 304, may suffer stress corrosion cracking in solutions containing chloride ions at temperatures over about 60°C. Stress corrosion cracking should be considered for all corrosion services where the corrosive liquid may contain chloride.

Toughness/Hardness

Austenitic stainless steels are inherently tough and 316 stainless steel is no different, maintaining the ductile fracture mode and high absorbed energy in impact tests to cryogenic temperatures (-200°C).

Pressure Vessels

AS1210, Pressure Vessels, allows the use of grade 316 up to a temperature of 800°C. The standard allows the use of higher design stresses for 316H at all temperatures.

High Temperature Corrosion

The generally accepted maximum service temperatures for grade 316 (and grade 304) in air are 870°C for intermittent service and 925°C for continuous service.

Cold Fabrication

Grade 316 is readily workable, by the standard methods of sheet metal working, with the exception that it cannot be oxygen cut. Plasma cutting is normal. The deep drawing capability of grade 316 is outstanding, because of its high austenite stability.

Forging

316 is one of the easier austenitic stainless steels to forge, at temperatures above 925°C.

Machinability

Grade 316 is relatively easy to machine, although more difficult than carbon steel. More power is required to machine grade 316. Cutting speed should be lower, the feed higher, tooling and equipment heavier. The machinability of 316 is about 60% that of AISI B1112 resulphurised free cutting carbon steel. A free machining version of 316 is available as bar.

Heat Treatment

Solution annealing is performed at 1065 - 1120°C, followed by rapid cooling to prevent the precipitation of the chromium carbides. 316 cannot be hardened by heat treatment. Stress relieving is rarely required due to the high ductility of 316.

Weldability

Grade 316 stainless steel is readily weldable by most fusion techniques (GTAW / TIG, GMAW / MIG / MAG, MMAW / stick, SAW), with no preheat, postheat or control of interpass temperature needed. It is usually welded with filler metals of the same grade, 316 or 316L (or the silicon containing versions) which retains corrosion resistance and strength. These grades are pre-qualified weld metals to AS1554.6:1994 for welding grade 316 to itself.

Chemical Composition

(AS1449 / ASTM A240 - Flat Products)

Mechanical Properties

(AS1449 / ASTM A240 - Flat Products)

Finishes

No1 (hot rolled, annealed and pickled), 2D (cold rolled), 2B (cold rolled, skin passed), N4 (polished).

Flat products are available surface protected with white polyethylene (PE) film. Protection with blue poly vinyl chloride (PVC) for deep drawing or black PVC (for heavy forming) is also available.

Physical Properties

(Typical, annealed)