Plates

Plates can be available in thicknesses ranging from 6mm to 80mm, in the following austenitic, ferritic, duplex, and martensitic grades:

• Austenitic Grades: They possess an austenite phase (which has a face-centered cubic, FCC crystal structure). FCC crystal structure gives the required ductility & toughness for these grades. This can be achieved by alloying steel having more than 16% chromium with sufficient nickel and/or manganese and nitrogen to maintain an austenitic microstructure at all temperatures, ranging from room temperature to its melting point.
• Ferritic Grades: They possess a ferrite phase (which has a body-centered cubic, BCC crystal structure). Ferritic stainless steels contain between 10.5% and 27% chromium with very little or no nickel. This ferrite microstructure is present at all temperatures due to the chromium addition, so they are not hardenable by heat treatment. They cannot be strengthened by cold work to the same degree as austenitic stainless steel. But they are magnetic, unlike Austenitic grades.
• Martensitic Grades: Martensitic structure (which has a body-centered tetragonal, BCT crystal structure) is formed when a high-temperature austenite phase is rapidly quenched to room temperature. Martensitic stainless steels offer a wide range of properties and are used as stainless engineering steels, stainless tool steels, and creep-resistant steels. They are magnetic, and less corrosion-resistant than ferritic and austenitic stainless steels due to their lower chromium content. Martensitic grade plates are supplied in the annealed condition.
• Duplex Grades: They contain a mixed microstructure of austenite and ferrite (usually a 50:50 ratio). They can offer higher yield strength compared to austenitic stainless steel, good corrosion resistance & good stress-corrosion cracking resistance.