Standard materials types of structural steel

When discussing the types of structural steel, it's essential to understand the various materials used and their unique properties, which cater to different applications in construction and manufacturing. Below is a breakdown of some common types of structural steel materials.

1. Carbon Steels

Carbon steel is a widely used type of steel that contains carbon as the primary alloying element, alongside other elements like zirconium, cobalt, and nickel in smaller amounts. The presence of carbon ranges from 0.05% to 2.1% by weight, with additional elements such as manganese (1.6%), silicon (0.6%), and copper (up to 0.6%) not exceeding specified limits. Carbon steels are classified based on their carbon content into the following categories:

- Low-Carbon Steel: Contains less than 0.3% carbon.

- Medium-Carbon Steel: Carbon content ranges from 0.3% to 0.6%.

- High-Carbon Steel: Contains 0.6% to 1% carbon.

- Ultrahigh-Carbon Steel: Carbon content ranges from 1.25% to 2%.

Carbon steel is the most prevalent type of steel, accounting for over 90% of all steel produced. Its versatility and affordability make it suitable for various applications, especially in structural pipes and tubing. However, due to its susceptibility to corrosion, protective measures are necessary when used in environments exposed to the elements.

2. High-Strength Low-Alloy Steels

High-strength low-alloy (HSLA) steel offers improved mechanical properties and greater resistance to corrosion compared to carbon steel. Unlike carbon steels, HSLA steels are not defined by a specific chemical composition but rather by specific mechanical properties. These steels typically contain low levels of alloying elements such as manganese (up to 2%), vanadium, titanium, molybdenum, or boron, which can be added singly or in combinations to enhance the material's properties. HSLA steels are particularly resistant to atmospheric corrosion, making them ideal for use in structural shapes and plates.

3. Forged Steels

Forged steel is known for its strength and durability, resulting from the process of forging, where steel is shaped by hammering or pressing it into a desired form. This process involves heating the steel to high temperatures and applying pressure, which causes the steel to deform and take on the intended shape. Forged steel components, such as gears, bearings, shafts, hinges, and valves, are often stronger and more durable than those made from cast or rolled steel.

4. Quenched and Tempered Alloy Steels

Quenched and tempered alloy steels undergo a heat treatment process to enhance their strength, hardness, and toughness. The quenching process involves heating the steel to a high temperature and then rapidly cooling it in a liquid medium, like water or oil, which creates a hard martensitic microstructure. The subsequent tempering process involves reheating the quenched steel to a lower temperature and then slowly cooling it, which softens the martensitic structure and increases the steel's ductility. This type of steel is commonly used in applications where high strength and durability are critical.