Crevice corrosion of 316 stainless steel in desalination

SAE 316L grade

stainless steel Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's r ...

, sometimes referred to as A4 stainless steel or marine grade stainless steel, is the second most common

austenitic stainless steel Austenitic stainless steel is one of the five classes of stainless steel by crystalline structure (along with '' ferritic'', ''martensitic, duplex and precipitation hardened''). Its primary crystalline structure is austenite (face-centered cubi ...

after 304/A2 stainless steel. Its primary alloying constituents after

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in fro ...

, are

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and ha ...

(between 16–18%),

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

(10–12%) and

molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lea ...

(2–3%), with small (<1%) quantities of silicon, phosphorus & sulfur also present. The addition of molybdenum provides greater corrosion resistance than 304, with respect to localized corrosive attack by

chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts ...

s and to general corrosion by reducing acids, such as

sulfuric acid Sulfuric acid ( American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

. 316L grade is the low carbon version of 316 stainless steel. When cold worked, 316 can produce high yield and tensile strengths similar to Duplex stainless grades. It is commonly used in chemical and

petrochemical Petrochemicals (sometimes abbreviated as petchems) are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable ...

industry, in

food processing Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing includes many forms of processing foods, from grinding grain to make raw flour to home cooking to complex indu ...

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field an ...

equipment,

medical devices A medical device is any device intended to be used for medical purposes. Significant potential for hazards are inherent when using a device for medical purposes and thus medical devices must be proved safe and effective with reasonable assura ...

, in

potable water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industri ...

treatment, in marine applications and architectural applications near the seashore or in urban areas.

Gallery

File:External Thread Galling.png, Pipe fitting of 316 steel (equivalent to A4 steel). File:Schmidt K5 fountain pen converter + 2.5 mm 316 Stainless Steel bearing ball.jpg, A fountain pen converter containing a 316 stainless ball of 2.5 mm diameter File:Orbital Welding 316L Stainless Steel.jpg, Two welded 316L steel pipes. File:316L Stainless Steel Unpolished.jpg, Unpolished 316L steel. File:SCC_of_stainless_steel_UNS_S31603.jpg, Stress corrosion cracking in 316L by synthetic seawater File:Laserengravingonsteel.jpg, Hose barb pipe fitting in 316L

References

{{SAE International Stainless steel

Gallery

See also

References