AISI 316 Stainless Steel - Grade 316 (UNS S31600)

AISI 316 Stainless Steel (UNS S31600)

AISI 316 stainless steel (UNS S31600) is one of the most widely used austenitic stainless steels. Due to the addition of Molybdenum (Mo), SS 316 has a great improvement in corrosion resistance and certain properties.

316L stainless steel (UNS S31603) is the low carbon version of AISI 316. SS 316 is better than SS 304 in terms of corrosion resistance, heat resistance and certain properties, but the price is higher than AISI 304, for more details, please check stainless steel grade 304 vs 316, and 316 vs 316L.

SS 316 Data Sheet & Specification

ASTM SAE AISI 316 stainless steel data sheet and specification are listed in the table below, including chemical composition and properties.

AISI 316 Chemical Composition

SS 316 chemical composition is given in table 1.

Table-1, AISI 316 stainless steel composition

Notes:

Grade 316 Stainless Steel Properties

AISI ASTM 316 stainless steel properties such as physical properties, mechanical properties, magnetic properties are summarized in the tables below.

Mechanical Properties

The following tables show AISI 316 grade stainless steel mechanical properties such as yield strength, tensile strength, elongation and hardness, etc.

Table-2, SS 316 stainless steel properties, data are for 25.4 mm (1 in.) diameter bar

Table 3, ASTM 316 stainless steel properties

SS 316 Material Physical Properties

The data sheet below shows SS 316 material physical properties, such as density, melting point, thermal conductivity, thermal expansion, magnetic, modulus of elasticity, specific heat capacity, etc.

316 Magnetic Properties

Type 316 steel is not magnetic, but may be weakly magnetic after cold working.

SS316 Heat Resistance

316 SS has good oxidation resistance in intermittent use below 871 °C and continuous use up to 927 °C in air. In the range of 427 °C – 857 °C, it is better not to continuously use SS 316, but when 316 stainless steel is continuously used outside this temperature range, it has good heat resistance. 316L stainless steel has better carbide precipitation resistance than AISI 316 and can be used in the above temperature range.

AISI SAE ASTM 316 Heat Treatment

AISI 316 stainless steel heat treatment are summarized in the following content, such as annealing, hardening, etc.

Solution Treatment (Annealing Temperature)

Annealing at a temperature range of 1010-1065 °C, then cooling rapidly. Type 316 stainless steel surface should be carefully cleaned before annealing and must be protected with vacuum, hydrogen or inert gas in order to prevent the formation of an oxide layer during the annealing process.

Homogenization Treatment

The temperature for homogenization heat treatment is about 1250 °C.

Forging Temperature

AISI 316 stainless steel typical forging temperature is 925-1260 °C (1700-2300 ℉).

Hardening

Type 316 SS cannot be hardened by heat treatment, but can be hardened by cold working.

Stress Relieving Temperature

When the weldment of 316 grade stainless steel is not suitable for complete annealing, the residual stress can be moderately lowered below 600 °C, which makes it have good creep resistance.

Cold Working

AISI 316 grade stainless steel is suitable for cold working such as cold heading, cold drawn and cold riveting, but it is more difficult than carbon steel.

Machining

AISI 316 stainless steel has higher strength and higher work hardening rate than carbon steel and low alloy steel, so it is more difficult to process. Therefore, greater power and lower processing speeds are required, which may result in shortened tool life and difficulty in obtaining a smooth surface.

Welding of AISI 316

Type 316 stainless steel has good weldability and does not require preheating, but requires a similar filler material composition but a high alloy content. To avoid weld cracking, ensure that the weld contains 5-10% ferrite during the welding process. To avoid weld corrosion, the carbon content can be reduced, for example using ultra-low carbon stainless steel 316L, stabilized stainless steel or adding niobium (Nb). For optimum corrosion resistance, softness and ductility, SS 316 may require subsequent reannealing after welding or heat treatment. Because chromium carbide with intergranular corrosion is dissolved during the annealing process.

Post weld heat treatment: If undertaken, 950-1150 °C (1740-2100 °F), or stress relief below 650 °C (1200 °F) to avoid weld decay.

Corrosion Resistance

AISI 316 stainless steel has better corrosion resistance than 304 stainless steel and has good corrosion resistance in the production of pulp and paper. Moreover, Type 316 SS also has good corrosion resistant in marine and aggressive industrial atmospheres.

The following is the application range of AISI 316 stainless steel corrosion resistance chart in chloride ion media for reference.

Applications of AISI SAE ASTM 316

The main uses of AISI 316 stainless steel are heat exchangers for pulp and paper equipment, dyeing equipment, film processing equipment, pipes, solenoid valves, clamps, spheres, valve bodies, valve seats, nuts, valve stems, flanges, and materials for exterior use in coastal areas, etc. Also used in marine environment and used as food grade stainless steel.

AISI 316 Equivalent

ASTM type 316 stainless steel equivalent to ISO, European EN (German DIN, British BSI, France NF), Japanese JIS and Chinese GB standard (For reference).

Table-3, type 316 stainless steel equivalent chart.