What is 316 Stainless Steel?
Stainless steel is a type of steel alloy containing a minimum of 10.5% chromium. Chromium imparts corrosion resistance to the metal. Corrosion resistance is achieved by creating a thin film of metal oxides that acts as protection against corrosive materials. A popular grade of stainless steel is stainless steel 316. Stainless Steel 316 is generally composed of 16 – 18% chromium, 10 – 14% nickel, 2 – 3% molybdenum, and about 0.08% carbon. The added molybdenum makes this grade more corrosion-resistant than the other types. Aside from those mentioned, other elements can be added to modify certain properties of the alloy. Stainless steel 316 is widely used in highly corrosive environments such as chemical plants, refineries, and marine equipment.
Stainless steel 316L has lower carbon content and is used in applications that subject the metal to risks of sensitization. The higher carbon variant is Stainless Steel 316H which offers greater thermal stability and creep resistance. Another widely used grade of stainless steel 316 is the stabilized 316Ti.
Different Versions of 316 SS
Stainless steel utilizes the principle of passivation wherein metals become “passive” or unreactive to oxidation from corrosive compounds found in the atmosphere and process fluids. Passivation is done by allowing the stainless steel to be exposed to air where it builds chromium oxides on its surface. To enhance the formation of the passive film, the alloy is introduced to a chemical treatment process where it is thoroughly cleaned by submerging it in acidic passivation baths of nitric acid. After cleaning with an acidic bath, the metal is then neutralized in a bath of aqueous sodium hydroxide. Descaling is also done to remove other oxide films formed by high-temperature milling operations such as hot-forming, welding, and heat treatment.
What is the Difference Between 316, 316L, 316H, and 316Ti?
- 316 Stainless Steel is an austenitic chrome-nickel stainless steel containing molybdenum. Next is the stainless steel important to 304. Compared with class 304, molybdenum has 316 better overall corrosion resistance, especially in the chloride environment with higher pitting and crevices corrosion resistance.
- 316L Stainless Steel is a low-carbon austenitic chrome-nickel stainless steel with the same corrosion resistance as type 316, but with the property of resistance to intergranular corrosion after welding.
- 316H Stainless Steel is a higher 316 carbon variant, which makes the steel more suitable for use at high temperatures. The equilibrium class 316Ti has a comparable mass. The expanded carbon content provides greater tensile strength and yield strength. The austenitic structure of the material has excellent toughness even at low temperatures.
- 316Ti Stainless Steel is a titanium alloy additive of 316 steel. This extension increases corrosion resistance, enhances the ability to resist pitting chloride solutions, and has enhanced strength at high temperatures, especially for sulfuric acid, hydrochloric acid, acetic acid, formic acid, and tartaric acid. Acid sulfate and alkaline chloride.
Uses of 316 SS
The most familiar uses of 316 Stainless Steel are in the construction of exhaust manifolds, furnace parts, heat exchangers, jet engine parts, evaporators, chemical processing equipment, pharmaceutical and photographic equipment, valve and pump parts, tanks, pulp and paper, and textile processing equipment and parts that are exposed to marine environments.
Properties of Stainless Steel
- It is a molybdenum-bearing grade & can be categorized under the austenitic steel category.
- It is extensively used in the marine sector, as it is corrosion-resistant and can even be utilized in harsh marine conditions as well.
- These are resistant to carbide precipitation when used in temperatures ranging from 425ºC to 860º
- As it is corrosion resistant, it is very used in various commercial and industrial applications as well as in high-chloride environments.