Science, Tech, Math › Science The 200 Series of Stainless Steels This family of steels was born out of a need to conserve nickel Share Flipboard Email Print Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Terence Bell University of British Columbia Carleton University Terence Bell wrote about commodities investing for The Balance, and has over 10 years experience in the rare earth and minor metal industries. our editorial process Twitter Twitter LinkedIn LinkedIn Terence Bell Updated March 10, 2020 The 200 series is a class of austenitic and highly corrosion-resistant stainless steels that are characterized by having low nickel content. They're also referred to as chrome-manganese (CrMn) stainless steel. Austenitic steels include both the 200 and 300 series. They're defined by their face-centered cubic structure. The crystal structure has one atom at each corner of the cube, and one in the middle of each face. This is different from ferritic steels, which are characterized by a body-centered cubic structure. Production of 200 Series Stainless Steels Nickel is the most commonly used element to produce this crystal structure, but a post-World War II nickel shortage led to the substitution of nitrogen for nickel in the production of some austenitic corrosion-resistant steels. The 200 series of stainless steels were born. Nitrogen alloyed in steel will also form a face-centered cubic structure, but it results in harmful chromium nitrides and it increases gas porosity. The addition of manganese allows more nitrogen to be safely added, but nickel can't be completely removed from the alloy. The 200 series stainless steels are consequently characterized by their nitrogen and manganese content. Production and demand for low-nickel stainless steels surged in the 1980s as nickel prices soared and, again, efforts were made to reduce the use of the metal. This led to the development of a huge production increase in India. Asia is now a major source for, and consumer of, this family of steels. Characteristics of the 200 Series of Stainless Steels Although it's corrosion-resistant, the 200 series has a lesser ability than the 300 series to protect against pitting corrosion. This occurs in environments that have high moisture and chlorine contents. The 200 series also have a lesser ability to protect against crevice corrosion, which results in stagnant liquid and high acid environments. The chromium content must also be reduced in order to decrease the nickel content, thereby lowering corrosion resistance. Series 200 stainless steels have excellent impact resistance and toughness, however, even in low and cryogenic temperatures. They're generally harder and stronger than 300 series steels, primarily due to their higher nitrogen content which acts as a strengthener. Neither the 200 and 300 series of stainless steels are magnetic because they're austenitic. Austenitic steels are more expensive than their ferritic counterparts, but the 200 series is cheaper to produce than 300 series steels because of its lower nickel content. The 200 series steels suffer from lower formability and ductility than 300 series grades, but this can be improved with the addition of copper. Applications for 200 Series Stainless Steels The range of applications for 200 series stainless steels is narrower than that of 300 series steels due to its lower corrosion resistance. It's not recommended for use in chemical environments, but it's found its way into many household items. Some applications for 200 series stainless steel include: Dishwashers and washing machinesCutlery and cookwareIn-house water tanksIndoor and noncritical outdoor architectureFood and beverage equipmentAutomobiles (structural)Automobiles (decorative) Grade Chemical Composition AISI UNS Cr Ni Mn N Cu 304 S30400 18.0-20.0 8.0-10.5 2.0 max. 0.10 max. - 201 S20100 16.0-18.0 3.5-5.5 5.5-7.5 0.25 max. - 202 S20200 17.0-19.0 4.0-6.0 7.5-10.0 0.25 max. - 204 Cu S20430 15.5-17.5 1.5-3.5 6.5-9.0 0.05-0.25 2.0-4.0 205 S20500 16.5-18.0 1.0-1.75 14.0-15.5 0.32-0.40 - Properties and Composition of Type 201 Stainless Steel An Introduction to Cryogenic Hardening of Metal What You Should Know About Metallurgical Coal Corrosion Prevention for Metals The Properties and Applications of Platinum The Major Applications of Steel Brass Alloy Additives Learn About Refractory Metals The Properties, Production, and Applications of Tin The History of Steel Top 10 Reasons Why America Should Get Rid of the Penny A List of Base Metals A Brief History of Lead Properties, Uses and Characteristics Trade Wars and their Effect on the Economy and You How Are Prices Determined In Metal Markets? What Is Mischmetal?