4 Types of Steel: Their Properties and Applications

Read through this guide, classification of steel into the 4 types of steel along with carbon steel types, stainless steel types and tool steel types.

Steel is known to the human beings since 1800 BC (4000 years ago). Today, it has become one of the most commonly manufactured materials in the world.

The modern steel industry is one of the largest manufacturing industries in the world with production of approx 2000 MTPA (Million Tonnes Per Annum).

Steel is not only used in civil construction, but there are innumerable products that are made of steel and we use them in our daily life.

What is Steel?

By definition, Steel is an alloy composed of a combination of iron and carbon with various elements. This new material "steel" has improved physical properties compared to iron and has special properties such as resistance to corrosion and heat. This article details the 4 types of steel: their properties and applications.

Elements such as manganese, phosphorus and sulfur are partially found in all grades of steel. Manganese provides beneficial effects to steel, but phosphorus and sulfur are impurities in steel and they are deleterious to the strength and durability of steel.

The amount of carbon as well as the level of impurities (sulphur, phosphorus) and additional alloying elements (manganese, nickel, magnesium, molybdenum, titanium, silicon, copper, chromium, etc.) determine the properties of each steel grade. The carbon content in steel can range from 0.1% to 2%.

Four Types of Steel: Their Classifications, Properties and Uses

This article details the types of steel and their properties & uses. According to the World Steel Association, there are over 3,500 different types of steel, which can be classified into four common types of steel depending on their chemical content or metal alloy contents:

1. Carbon Steel
2. Alloy Steel
3. Stainless Steel
4. Tool Steel

1. Carbon Steel

Carbon steel is the kind of steel contains trace amounts of alloying elements such as Manganese, Silicon and Copper.

Carbon is the hardest element, so products made of carbon steel are also very hard. Keeping different percentages of carbon produces steel with different properties. However, higher carbon content often turns into a stronger but more brittle steel.

Types of Carbon Steel

Carbon steels can be further classified into following four groups depending on the level of carbon content:

A.) Low Carbon Steel (Mild Steel),
B.) Medium Carbon Steel,
C.) High Carbon Steel and
D.) Ultra-high Carbon Steel.

A.) Low Carbon Steel (Mild Steel)

B.) Medium Carbon Steel

C.) High Carbon Steel

D.) Ultra-High Carbon Steel

Note: Since carbon steels do not contain chromium, they tend to corrode faster than almost every other types of steel.

Carbon Steel: Types, Properties and Uses (Summary)

2. Alloy Steel

Alloy steel is a type of steel that contains alloying metals (aluminum, manganese, silicon, nickel, copper, chromium and titanium) in varying proportions. These alloy metals manipulate the properties of steel, such as its hardenability, corrosion resistance, strength, formability, weldability or ductility. These properties might vary according to the proportion of metals present. Alloy Steel is used in pipelines, auto parts, electric motors, power generators, and transformers.

3. Stainless Steel

Stainless steel is a type of steel that usually contains 10-20% chromium as the main alloying element and includes some other alloys. Stainless steels, that contain over 11% chromium, have about 200 times more resistant to corrosion than mild steels.

Types of Stainless Steel

Based on its crystalline structure, stainless steel can be further classified into three groups:

A.) Austenitic,
B.) Ferritic and
C.) Martensitic.

A.) Austenitic

B.) Ferritic

C.) Martensitic

4. Tool Steel

Tool steel is a type of steel that contains hard metals like tungsten, molybdenum, cobalt and vanadium in varying quantities to increase its durability and heat resistance, making them ideal for cutting and drilling equipment.

Types of Tool Steel

There are 7 types of tool steels.

A.) Water-Hardening Tool Steels

B.) Shock-Resisting Tool Steels

C.) Mold Steels

D.) Cold-Work Tool Steels

• A-grade steel is used in coining, cams, die bending, arbors and blanking.
• O-grade steel is used in chasers (thread-cutting), arbors, bushings and die blanking.
• D-grade steel is used in die-casting die blocks, drawing dies and forging dies.

E.) Hot-Work Tool Steels

F.) High-Speed Steels

G.) Special Purpose Tool Steels

F-type steels are water-hardening tool steels. These steels are ideal for applications that require high wear resistance but not high temperature or shock resistance. F-type steels are commonly used for paper-cutting knives, broaches, burnishing tools, reamers and plug gauges.

Grades of Steel

Steel Classifications: On The Basis of Variety of Factors

Steel can also be classified by a variety of different factors such as:

1. Composition: Carbon range, Alloy, Stainless.
2. The production method: Continuous cast, Electric furnace, etc.
3. Finishing method used: Cold Rolled, Hot Rolled, Cold Drawn (Cold Finished), etc.
4. Form or shape: Bar, Rod, Tube, Pipe, Plate, Sheet, Structural, etc.
5. De-oxidation process (oxygen removed from steelmaking process): Killed & Semi-Killed Steel, etc.
6. Microstructure: Ferritic, Pearlitic, Martensitic, etc.
7. Physical Strength (as per ASTM standards).
8. Heat Treatment: Annealed, Quenched & Tempered, etc.
9. Quality Nomenclature: Commercial Quality, Drawing Quality, Pressure Vessel Quality, etc.

Conclusion

Different types of steel in construction are produced according to the properties required for their applications. Various grading systems are used to distinguish steels based on these properties. Hope you have liked this guide on types of steel.

FAQs on Types of Steel