Classification of Alloy Structural Steel

Classification of Alloy Structural Steels

Alloy structural steels are a group of structural steels that have an alloying elements added to their range of compositions. These alloying elements increase their strength, hardness and corrosion resistance compared to normal carbon steels. Alloy structural steels are divided into two broad categories depending on the type of alloying elements used. These categories are low-alloy steels and high-alloy steels.

Low-alloy steels are steels that contain limited amounts of alloying elements such as carbon, manganese and silicon. These steels are considered to have low-alloy content as the alloying elements are present in very small amounts. Low-alloy steels are used in applications where a high strength steel is needed without the additional cost associated with high-alloy steels. Low-alloy steels are used primarily in the production of automotive components and machinery. Low-alloy steels can be further categorized into martensitic grades, bainitic grades, and ferritic grades.

High-alloy steels are steels that contain larger amounts of alloying elements such as copper, nickel and chromium. These steels are considered to have a high-alloy content as the alloying elements are present in large amounts. High-alloy steels are used in industries where a highly corrosion resistant steel is needed. These steels are used in the production of components used in a marine or chemical processing environment. High-alloy steels can be further categorized into austenitic grades, duplex grades, and martensitic grades.

Alloy structural steels are employed in a wide range of applications. These steels can be used in automotive components, machinery components, and components that need to be highly corrosion resistant. Alloy structural steels are usually welded, forged, or rolled into the desired shape, depending on the application. The higher strength, hardness and corrosion resistance offered by alloy structural steels allow for the design of lighter, stronger, and more efficient components.

Alloys structural steels are made of a combination of several different elements. The most common alloying elements are carbon, manganese, and silicon, as well as other elements such as chromium, nickel, and copper. Each of these elements contributes differently to the properties of the steel, allowing for a wide variety of potential applications. The choice of alloying elements and their relative quantities play a key role in determining the properties of the resulting alloy structural steel.

In conclusion, alloy structural steels are a form of steel with added alloying elements to improve strength and hardness, as well as corrosion resistance. These steels can be divided into two broad categories- low-alloy steels, and high-alloy steels. Low-alloy steels are used primarily in the automotive and machinery industries, while high-alloy steels are used in industries where a highly corrosion resistant steel is needed. The choice of alloying elements and their relative quantities play an important role in determining the properties of the resulting alloy structural steel.

Low alloy structural steels are a class of steels designated by their number of alloying elements, which combined form a range of temperature and strength aspects. Depending on the number of the alloying elements, low alloy structural steels can be sub-classified as:

1.Low-Alloy Steel with 2-9% Alloying Elements: These are mainly used in welded and/or hot-rolled construction components. Examples of such steels include Naval Grade and ASTM A709.

2.High-Strength Low-Alloy Steel: These steels contain up to 2-9% of alloying elements and achieve their strength through the quenching process. Examples of such steels include ASTM A572 and HSLA.

3.Weldable High-Strength Low-Alloy Steel: These steels contain between 2-9% alloying elements and are specially designed for welding and/or hot rolling. Examples of such steels include ASTM A588.

4.Ultra-High Strength Low-Alloy Steel: These are high-strength steels, usually created through the quenching process and contain up to 25% of alloying elements. Examples of such steels include DuPont® Zytel® 721 and ASTM A514.

Low alloy structural steel can be an excellent choice for a variety of industrial applications, due to its greater strength and flexibility, as well as its good weldability and high tensile strength. While other steel alloys may have higher performance attributes, low alloy structural steels offer a cost-effective alternative that can meet most applications requirements.

Overall, low alloy structural steels are a great option for many industrial applications, due to their high strength, weldability and versatile use.