Alloy steel is a versatile material widely used in the construction sector for various purposes. Alloying elements contain excellent hardness, toughness, strength, and wear resistance. Due to its load-bearing capacity and light weight, it can meet various structural requirements.
Steel is classified into various types, including galvanized steel, alloy steel, shaped steel, etc. In this article, you’ll explore in detail about alloy steel, along with its applications, benefits, and types.
What is Alloy Steel?
Alloy steel is primarily composed of carbon and steel, along with various chemical elements such as manganese, nickel, copper, etc. The percentage of these added elements is tailored to enhance the desired properties of the final product. It typically ranges from 1.0% to 50% of the overall weight of the steel structure. These quantities may be adjusted to make some improvements like strength, ductility, elasticity, and resistance to oxidation.
Properties of Alloy Steel
Alloy steel includes various chemical elements; each has its own unique properties. Their functionalities can greatly vary due to the differing quantities added in alloy steel.
For example, the elements mixed at less than 5% can improve mechanical properties like strength and hardening ability. If it is added up to 20%, you can increase the steel’s stability and corrosion resistance even at high and low temperatures.
Some elements of alloy steel, their weight, and functionalities are mentioned in the table below:
| Elements | Weight (%) | Functionality |
| Copper | 0.1 to 0.4 | Excellent corrosion resistance |
| Manganese | 0.25-0.40 | Allows slower cooling, hence the risk of brittleness is reduced. |
| Nickel | 2 to 5, 12 to 10 | Promotes toughness and corrosion resistance properties in alloy steel. |
| Chromium | 0.5 to 2.0 | Beyond corrosion resistance, they provide excellent strength, tempering, and hardness. |
| Vanadium | 0.15 | Increased impact resistance, hardness, and abrasion resistance. |
| Sulfur | 0.08 to 0.15 | Improved machinability and corrosion resistance. |
| Tungsten | 0.8- 24 | Enhanced structural integrity, increased heat resistance capacity and higher melting point. |
Types of Alloy Steel
In general, alloy steel is composed of mixing steel with a number of other elements to achieve the desired properties and traits. It is broadly classified into three types: low alloy steel, medium alloy steel, and high alloy steel. They are explained below:
Low Alloy Steel
It is a ferrous material with excellent mechanical properties due to the presence of materials like chromium, nickel, and molybdenum. The concentration of these elements is typically less than 8% of the total composition. The primary role of these elements is to optimize the mechanical properties and increase toughness after heat treatment.
Medium Alloy Steel
Medium alloy steel is a versatile alloy material widely used for its balanced carbon content and other useful qualities. It includes alloying elements like silicon, manganese, nickel, chromium, and molybdenum in between the moderate amount of 1% and 5%. They are used in various applications, including energy, automotive and manufacturing industries, and construction.
High Alloy Steel
It contains high alloy content, which is more than 8% of its total composition. They provide greater resistance to corrosion and improve mechanical properties compared to carbon steel. It has been widely used from kitchen utensils to medical equipment, including cars and industrial machinery. This is the most popular alloy, which contains at least 10.5% chromium, and it is a bit more expensive than low alloy steel.
Uses and Applications of Alloy Steel
Alloy steel includes enhanced alloy elements, which are used in a wide variety of industries. Here are some common uses and applications:
Construction Industry: Alloy steel plays a vital role in the construction industry. It is used to create a comprehensive range of products, including beams, girders, pipes, sheets, plates, rods, bars, etc. If it is a large-scale infrastructure project, alloy steel involves the creation of motorway barriers, railways, bridges, and electrical pylons.
Manufacturing Industry: Manufacturing industries primarily depend on alloy steel. It’s strength, malleability, and durability are indispensable in the manufacturing of machinery, tools, and equipment. Importantly, steel alloy is used for constructing extensive manufacturing facilities, such as factories and production plants. It improves efficiency and longevity of machinery, helping increase productivity and reduce maintenance costs.
Automotive Industry: Alloy steel is widely known for its strength, durability, excellent corrosion resistance properties and is used in the production of suspension systems, frames, body parts, and engine components. The demand for lightweight materials is increasing, which boosts the development of high-strength alloy steels. It is because they improve fuel efficiency at reduced weight.
Medical Industry: Medical tools and equipment require excellent strength, durability, and biocompatibility. That’s why alloy steel is considered as the finest choice for implants, surgical instruments, and dental tools. Using reliable and long-lasting equipment improves patient outcomes.
Advantages of Alloy Steel
Alloy steel has several outstanding benefits and has been preferred in various manufacturing sectors. Compared to other materials, alloy steel has the following advantages:
- Stronger and harder than most other materials
- Increased ability to get harder
- Highly resistant to corrosion
- Excellent load-bearing capacity
- High melting point
- Abrasion resistance
- Increased durability
How is Alloy Steel Manufactured?
Traditionally, steel alloys are manufactured using predetermined proportions of certain pure elements like scrap steel, iron ore, and alloying elements. Initially, they are prepared and melted in furnaces.
In solid forms, an adequate mixing is extremely slow and time-consuming; however, it can be easily accomplished in liquid states. The molten steel is then refined, cast, rolled, and formed into the required shapes.
To achieve the desired properties, heat treatment processes are applied, like annealing, hardening, and tempering. Finally, the alloy steel is ready, which is then inspected and ready for use.
Final Lines
Alloy steel is used in various applications and industries. Based on the base material and properties, its uses may differ. Based on the industry requirements, you can customize the proportion of elements. Thus, alloy steel is a versatile material that is crucial for many industries