What is Martensitic stainless steel also known as?

• A. 200 series stainless steel
• B. 300 series stainless steel
• C. 400 series stainless steel
• D. 500 series stainless steel

Answer: (C)

Martensitic stainless steel is primarily identified as 400 series stainless steel. This classification is significant because martensitic stainless steels have a distinctive structure that results from the heat treatment process, leading to their unique properties, such as higher hardness and strength. This series typically contains between 12% and 18% chromium and is known for its ability to be hardened by heat treatment, making it suitable for various applications, particularly in surgical instruments and tools where durability is essential.

Each series of stainless steel has specific properties and compositions. The 200 series, for example, is austenitic and contains manganese instead of nickel, while the 300 series is also austenitic, known for excellent corrosion resistance. The 500 series, which consists mainly of specialty steels, does not pertain to martensitic stainless steel. Thus, understanding the classification helps in selecting the right stainless steel for the intended use, especially in the medical field where biocompatibility and strength are critical.