Which type of steel contains intentionally added materials to change its properties?

Alloy steel is defined by the intentional addition of various elements other than carbon to enhance its mechanical properties, corrosion resistance, and overall performance. The primary purpose of these alloying elements, which can include chromium, nickel, molybdenum, and vanadium, is to improve attributes such as strength, ductility, and toughness, or to provide specific characteristics required for particular applications.

For instance, adding chromium can enhance hardness and resistance to wear, while nickel can improve toughness and strength at low temperatures. These tailored adjustments allow alloy steel to be used effectively in a wider range of environments and applications compared to other types of steel. In contrast, other types of steel, such as carbon steel, primarily derive their properties from the carbon content alone and do not include similar levels of intentional modifications.

In stainless steel, while there are some alloying elements that contribute to corrosion resistance, it is still primarily categorized for its high chromium content. Tool steel is another specialized category mostly designed to maintain its hardness and abrasion resistance during high-stress applications, but its classification is more about the heat treatment processes rather than the intentional addition of multiple alloying elements for broader property modifications. Thus, alloy steel stands out as the correct choice for steel types with intentionally added materials