Austenitic stainless steel: Austenitic stainless steel is the most common category of stainless steel and is characterized by its high levels of chromium (typically 18% or more) and nickel (typically 8% or more). It has a face-centered cubic (FCC) crystal structure and is non-magnetic. Austenitic stainless steel is known for its excellent corrosion resistance, formability, and weldability, and is used in a wide range of applications.
Ferritic stainless steel: Ferritic stainless steel contains lower levels of nickel than austenitic stainless steel (typically less than 2%) and higher levels of chromium (typically around 12% to 27%). It has a body-centered cubic (BCC) crystal structure and is magnetic. Ferritic stainless steel is known for its good corrosion resistance, especially in mildly acidic or alkaline environments, and its good high-temperature oxidation resistance.
Martensitic stainless steel: Martensitic stainless steel is characterized by its high strength and hardness. It contains moderate levels of chromium (typically around 11% to 17%) and can also contain small amounts of nickel, molybdenum, and other alloying elements. Martensitic stainless steel has a body-centered tetragonal (BCT) crystal structure and is magnetic. It is commonly used in applications that require high strength, such as in cutlery, knives, and turbine blades.
Duplex stainless steel: Duplex stainless steel contains roughly equal proportions of austenitic and ferritic phases, resulting in a mixed microstructure. It typically contains higher levels of chromium (around 19% to 28%) and lower levels of nickel (around 4.5% to 8%) than austenitic stainless steel. Duplex stainless steel is known for its excellent corrosion resistance and high strength, making it suitable for use in applications such as chemical processing, oil and gas production, and marine environments.
Precipitation-hardening stainless steel: Precipitation-hardening stainless steel can be hardened by heat treatment and precipitation of small particles within the microstructure. It includes grades such as 17-4PH and 15-5PH, which are commonly used in aerospace and other high-performance applications.
