See all Blog Posts Stainless Steel | The Four Types Steel (Part 3) Category: Stainless Steel, Steel Posted: March 23, 2015 This article is the third in a four-part series on the different types of steel. Read Part 1. The main alloying element in Stainless steels is chromium (typically between 10-20%). Stainless Steel is valued due to its high corrosion resistance. Stainless steel is about 200 times more resistant to corrosion than mild steel. Stainless steel can be divided into five groups: Austenitic: Austenitic steels form the largest portion of the global stainless steel market and few of its versatile usages would be food processing equipment, kitchen utensils and medical equipment. Austenitic stainless steels are the most weld-able of the stainless grades and can be divided rather loosely into three groups: common chromium-nickel (300 series), manganese-chromium-nickel-nitrogen (200 series) and specialty alloys. These metals are non-magnetic and not heat-treatable. Ferritic: Ferritic steels contain trace amounts of nickel, 12-17% chromium, less than 0.1% carbon, along with other alloying elements, such as molybdenum, aluminum or titanium. They can have good ductility and formability, but high-temperature strengths are relatively poor when compared to austenitic grades. Some ferritic stainless grades (such as types 409 and 405) cost less than other stainless steels. These metals are magnetic but are not heat treatable, they can be strengthened by cold working. Martensitic: Martensitic steels contain 11-17% chromium, less than 0.4% nickel and up to 1.2% carbon.The carbon content of this harden-able steel affects forming and welding. To obtain useful properties and prevent cracking, preheating and post-weld heat treatment is required. Martensitic stainless steels, such as types 403, 410, 410NiMo and 420 are magnetic and heat-treatable. These Stainless steels are used in knives, cutting tools, as well as dental and surgical equipment. Duplex: Primarily used in chemical plants and piping applications. Duplex stainless steels typically contain approximately 22-25% chromium and 5% nickel with molybdenum and nitrogen. Duplexes have higher yield strength and greater stress corrosion cracking resistance to chloride than austenitic stainless steels. Precipitation Hardening: This is a chromium-nickel stainless that also contains alloying additions such as aluminum, copper or titanium. These alloys allow the stainless to be hardened by a solution and aging heat treatment. They can be either austenitic or martensitic in the aged condition. Choosing a particular type of stainless steel can depend on the application and your requirements. Consider things like: Environment Corrosion and Corrosion resistance Tarnish and oxidation resistance Pitting Crevice corrosion Buy Stainless This article is the third in a four-part series on the different types of steel. Read Part 4 to learn more about Tool Steel grades and its attributes. Metal Supermarkets Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985. At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminum, tool steel, alloy steel, brass, bronze and copper. We stock a wide range of shapes including: bars, tubes, sheets, plates and more. And we can cut metal to your exact specifications. Visit one of our 100+ locations across North America today. Share: Facebook Twitter LinkedIn E-Mail Related blog articles What is the Spark Test? What is Oxygen Free Copper? What is Abrasion Resistant Steel?