Martensite (stainless steel) contains 4 to 26% chromium and a maximum of what percentage of nickel?

Martensitic stainless steel is characterized by its composition, which typically includes a significant amount of chromium and a limited amount of nickel. The correct answer highlights that martensitic stainless steel can contain up to 2.5% nickel.

Nickel is important in stainless steel as it affects the corrosion resistance and overall mechanical properties of the alloy. However, martensitic stainless steels are designed with a higher chromium content for strength and hardness, and they prefer lower nickel content compared to other types of stainless steels, like austenitic stainless steels, which can have much higher nickel percentages for greater ductility and corrosion resistance.

Understanding this composition is crucial, as the amount of nickel influences the steel's structure and properties. In martensitic stainless steels, high chromium levels lead to the formation of martensite upon quenching, whereas excessive nickel could transition the steel towards an austenitic structure, thereby altering desired characteristics such as hardness and tensile strength.