Austenitic SS 316

Austenitic SS 316

A stainless steel highly resistant to general corrosion, Austenitic SS 316 outranks conventional 302/304 nickel-chromium stainless steels. The 316 SS popular characteristics are excellent forming chloride capabilities, higher creep resistance to rupture, tensile strength at high temperatures, anti-corrosion and resistance to industrial solvents.

SS 316 perfectly fits into varied shapes like wires, ribbon strips, sheets and foil sizes. Found across cookware, cutlery, hardware, surgical instruments, industrial equipments and also in large-scale building construction materials (skyscrapers, towers etc.), the Austenitic SS 316 grade stainless steel is also used in stainless steel cylinders and tanks. They offer exceptional resistance in acidic and hard waters.

Made up of 18% chromium, 14% nickel and 0.03% carbon, this composition enables corrosion resistance and ductility. Austenitic SS 316 grade negatively responds to magnetic fields, so it is applied in metals with non-magnetic properties. Austenitic SS 316 grade is essentially non-magnetic because of its magnetic field intensity and behavior of electrons.

SS 316 steel contains 2%-3% molybdenum, which improves pitting resistance in chloride ion solutions and strengthens at high temperatures. The austenitic SS 316 ranks superior in domains of pitting resistance and crevice corrosion in chloride environments. The structure also gives these grades excellent toughness, even in cryogenic temperatures.

Austenitic SS 316 grade is suitable for applications near coastal areas. For instance, cities near the shore use Stainless Steel 316 in constructing buildings, railings, gates etc.

Comparatively more resistant than 304SS, the 316 SS is excellent in the range of atmospheric environments and even in corrosive media. It is subject to stress corrosion cracking above about 60°C. SS 316 is considered resistant to potable water with upto about 1000 mg/L chlorides at ambient temperatures, reducing to about 500mg/L at 60°C.

There are numerous 316 stainless steels, the commonly used are the L, F, N, and H variants.

The “L” designation implies less carbon content than 316. Alloy 316/316L stainless steel provides elevated temperature tensile, creep and stress-rupture strengths, as well as outstanding formability and weldability. Grade 316H with its higher carbon content has application at elevated temperatures, as does the stabilised grade 316Ti.

With 0.08% maximum carbon content, the Austenitic SS 316 L grade of stainless steels is used in non-welded parts and equipment. If used in welded applications, it is for light gauge applications. 316L grades is immune to sensitisation (grain boundary carbide precipitation), where short term exposure is required. Thus, it is used in heavy gauge welded components measuring over 6mm.

Both SS 316 and 316L exhibit a better corrosion resistance and are stronger at elevated temperatures. They are both non-hardened by heat treatment and can be formed, pulled or pushed through a die or smaller hole.

Stainless steel 316 resists oxidation in intermittent service upto 870°C and in continuous service upto 925°C. If subsequent aqueous corrosion resistance is important, continuous use of SS 316 in the 425°-860°C range is not recommended. Grade 316L is resistant to carbide precipitation and can be used in the aforementioned temperature range.

Alloy 316/316L is non-magnetic in the annealed condition, but becomes slightly magnetic as a result of cold working or welding. It can be welded and processed by standard shop fabrication practices. SS 316 undergoes solution annealing process in 1010°-1120°C range and then cools.

SS 316 has notable weldability by all standard fusion methods, both with and without filler metals. Heavy welded sections in Grade 316 require post-weld annealing for maximum corrosion resistance, unrequired for 316L. For heavy section welding, Grade 316Ti may be used as an alternative. Applications

  • Chemical, Pharmaceutical industry
  • Surgical, medical tools
  • vPaper industry
  • Petroleum Industry
  • Refinery equipment
  • Heat exchanger
  • Marine equipment
  • Fmcg Industry