2205 is the most common grade of duplex stainless steel casting, while 316 is usually regarded as marine grade stainless steel type in investment casting process. There are many factors to consider when deciding 2205 duplex stainless steel or 316 stainless steel for casting. Experienced in stainless steel investment casting, CFS foundry well know the difference between 316 stainless steel casting and 2205 duplex stainless steel casting.
Both grade 316 and 2205 stainless steel can be classified as marine grade stainless steel casting type, making them suitable for casting stainless steel components used in coastal locations or other areas where excessive chloride is present. Compared with 316 stainless steel castings, marine grade 2205 duplex stainless steel castings contains higher levels of Chromium, Nickel, Molybdenum, and Nitrogen. This results in a stronger stainless steel casting product with almost double the corrosion resistance of marine grade 316 stainless steel castings. To give you a good idea of it’s durability, marine grade 2205 stainless steel castings are often used on oilfield and marine hardwares. It is less likely to suffer from fatigue corrosion, stress corrosion cracking, chloride pitting and crevice corrosion, and sulphide stress corrosion. Therefore, if used for external glass balustrades, 2205 duplex stainless steel casting would add the serving life of the glass fittings. It would look its best for longer whilst maintaining its purpose of providing an effective safety feature.
Another difference between the these stainless steel grades is their microstructures. Grade 316 stainless steel casting has an austenitic microstructure (consisting of austenite, which is a non-magentic solid solution of iron with an alloying element). Grade 2205 Duplex stainless steel has as a ferritic-autentistic microstructure (consisting of 50% ferrite and 50% austenite, hence the term Duplex). Due to the their ferrite content, 2205 duplex stainless steel casting are therefore magnetic, and the duplex structure makes for higher strength, with higher resistance to stress corrosion cracking.
In terms of cost, 2205 duplex stainless steel casting is more expensive than 316 stainless steel casting due to the higher raw material cost. What’s more, few stainless steel foundries can cast 2205 duplex stainless steel in China for its limited casting technology.
In CFS Foundry, we can supply custom stainless steel casting service for both 2205 and 316 stainless steel grades. Any inquiry on stainless steel investment casting project, pls let us know!
