Steel Casting: Meaning, grades, process, properties, types, uses

Steel casting is used in several industries. Steel casting’s versatility makes it an ideal choice for a wide range of industries. Here is more about the properties of steel casting, process, grades and so on.

Meaning of steel casting

Steel casting is a manufacturing process and different kinds of steel are used in steel casting. The casting process mainly involves molten steel poured into a cast to form a desired shape. Steel casting is usually used when cast iron lacks the required strength. In other words, steel is steel casting is used in applications where strength is of utmost importance.

Properties of steel cast

Properties of steel casting include the following:

• Strength: As mentioned earlier, steel casting is known for its strength and is hence preferred in applications where strength is a key exception.
• Hardness: Steel casting displays excellent hardness. It can further be increased with further treatments such as heat treatment.
• Ductility: Steel castings feature excellent ductility. Meaning, they have an ability to deform without fracturing under tensile stress.
• Wear resistance: Steel castings are known for their wear resistance. This is an important feature in industries where abrasion and wear are expected.
• Corrosion resistance: Stainless steel castings display the most corrosion resistance and hence are the preferred choice in corrosion-prone industries such as chemicals, petrochemicals, marine, oil and gas, etc.
• Machinability: Despite strength and hardness, steel castings easier to machine. The level of ease depends on the grade of steel used. Machinability is an important feature in the engineering fields where precision machining is of utmost importance.

Some of the other properties of steel casting include:

• Toughness
• Smoother surface finish
• Heat resistance
• Dimensional accuracy

Cast steel vs. cast iron

Now, one may wonder what the difference between cast iron and steel cast is. Here is the difference:

	Cast iron	Steel cast
Carbon content	The carbon content in cast iron is 2-4%.	The carbon content in steel casting is less than 2%.
Mechanical properties	Cast iron is known for hardness, wear resistance, etc.	Steel casting is known for high tensile strength, ductility, impact resistance, etc.
Weight	Cast iron has a higher density and hence it is heavy for a given volume.	Steel casting has lower density and hence is used in industries where lightweight is important.
Machinability	It can be challenging to machine	Steel casting is comparatively easier to machine.
Application	It is used in limited applications such as engine blocks, cookware, pipes, etc.	It is used in a wide range of industries including marine, chemical, construction, etc.
Cost	It is cheaper than steel casting.	Higher material cost makes it expensive as compared to cast iron.

Process of steel casting

There are various types of steel casting. However, here are some of the key steps of the steel casting process.

Creating the master pattern:

Creating a pattern of the desired part is created. This pattern is created with a similar shape to that of the desired product, called a pattern.

Moulding:

Then, the pattern is placed in a container. The moulding material is then packed to create a mould cavity. This cavity defines the shape of shape of the steel part.

Melting

Steel is then melted in a furnace at a high temperature of more than 1,500 degrees Celsius. Then, steel is molten and poured into a mould.

Solidifying stage

The molten steel is left to cool itself in the shape of a cavity. Depending on the size and shape, solidification takes a few minutes to a few hours.

Removal

After the steel is solidified and cooled down, it is safely removed from the mould.

Finishing

Once the mould is removed steel casting is ready. Depending on need and application, casting may undergo further treatments such as heat treatment, surface finishing, and so on.

Types of steel casting

Seel casting processes are done in various types. Here are some of the commonly used casting processes.

• Sand casting:
• Investment casting
• Die casting
• Centrifugal casting

Grades of steel casting

As mentioned earlier, different kinds of steel are used for different kinds of applications. Expectations from casting define their grades. Some of the commonly used grades are mentioned below:

ASTM A27

It is a grade specification developed for carbon steel castings. Grade ASTM A27 is mainly used for general applications.

ASTM A216

ASTM A216 grade is a type of casting alloy made up of iron and carbon. Features of the grade include corrosion resistance, heat resistance, wear resistance, and so on. It is generally used in applications where high strength is a requirement. It is a suitable grade in applications where welding is a necessity.

ASTM A352

ASTM A352 grade of steel casting is generally used in pressure-containing parts such as valves, flanges, fittings, and so on. This grade of casting receives heat treatment.

ASTM A487:

This grade of steel casting is suitable for the chemical and petrochemical industry. It features high strength and corrosion resistance.

ASTM A148

It is a high-strength steel casting mainly used for structural purposes. Meaning it is in the construction and industrial equipment industries.

Some of the other types of steel casting grades include:

• ASTM A732
• ASTM A743
• ASTM A744
• ASTM A890
• ISO 3755

Steel casting: Uses

Here are some of the applications of steel casting.

Automotive

Steel is an important raw material for the automotive industry. Steel casting features lower density and hence, is known for its lightweight. This coupled with other properties such as wear resistance, corrosion resistance, etc., make it an ideal choice for the automotive industry.

Construction:

High-strength steel castings such as ASTM A148 find applications in structural steel making it an ideal choice for the construction industry.

Industrial machinery:

Steel casting’s wear resistance makes it a choice of material for industrial machinery applications.

Chemical& petrochemical

Steel casting is widely used in the chemical industry for making pressure-containing parts such as valves, flanges, fittings, and so on

Some of the other industries where steel casting is used include:

• Aerospace and defence
• Railways
• Marine
• Food processing
• Pharmaceutical
• General engineering