What is grade 316 Stainless steel?

Stainless steel 316 and 316L are an austenitic grade, also known as 1.4401 and 1.4404. Grade 316 is second only to 304 in commercial importance and accounts for about 20% of all stainless steel produced. It is often referred to as marine grade steel.

 

Corrosion resistance

 

Type 316 has excellent resistance to corrosion when exposed to a range of corrosive environments. For this reason, it is often selected for more aggressive locations such as sea-front buildings, fittings on piers and wharfs. While it is not completely rust-proof, this alloy has a greater corrosion resistance compared to other common grades of stainless steels. It is considerably more resistant to solutions of chlorides, bromides, sulphuric acid, iodides and fatty acids at high temperatures.

 

Qualities

 

This grade is durable and easy-to-fabricate, weld, clean and finish. It is non-magnetic in the annealed condition, but can become slightly magnetic as a result of cold working or welding. It is easily welded and processed by standard metal fabrication practices. Grade 316 stainless steel possesses excellent toughness, even at cryogenic temperatures.

 

Molybdenum

Type 316 contains 16% chromium, 10% nickel and 2% molybdenum. The molybdenum gives it improved overall corrosion resistance over 304 and particularly higher resistance to crevice corrosion and pitting in high chloride environments. Initially designed for paper mill machinery for its resistance to most chemicals involved, it is now also favoured in the textile and photographic industries. Stainless steel that contains molybdenum is required in the manufacture of some pharmaceuticals in order to avoid excessive metallic contamination.

 

Low carbon 316

The low carbon version of 316 stainless steel is 316L and is immune to grain boundary carbide precipitation. This makes it well suited for use in heavy gauge (over about 6mm) welded components. This low-carbon grade is ideal for handling paper pulp as well as for the production of rubber, rayon, textile bleaches and high-temperature industrial equipment. It is also the preferred grade for medical implants. Type 316L stainless steel is used extensively for weldments where its immunity to carbide precipitation from to welding assures optimum corrosion resistance.

High nitrogen 316

316N is the high nitrogen grade. It has increased resistance to pitting and to corrosion in crevices and is used for chemical handling accessories.

Industries

Type 316 stainless steel is the ideal alloy for electrical enclosures used in coastal areas, marine applications which are subject to sea sprays and industrial equipment exposed to corrosive chemicals. Industries which commonly use grade 316 include:

• Textiles

• Marine

• Photographic

• Food preparation

• Brewing

• Pharmaceutical

 

Applications

Common applications for which grade 316 stainless steel is preferred include:

• Exhaust manifolds

• Jet engine parts

• Pharmaceutical equipment

• Heat exchangers

• Photographic equipment

• Chemical equipment

• Tanks

• Furnace parts

• Evaporators

• Parts exposed to marine atmospheres

• Tubing

 

 

Surgical steel is made from subtypes of type 316 stainless steel