Introduction

Cast iron and cast steel are both types of metals used in a variety of projects. But what is the difference between them? Which one is right for your project?

They are both common materials used for castings. They both have their own unique properties and advantages.

In this article, we will discuss the differences between cast iron and cast steel, as well as their advantages and disadvantages. We’ll help you decide which one is the best choice for your next project!

Raw Material

Cast iron is made from pig iron, which is an iron-carbon alloy. Cast steel is made from pure iron. Due to the difference in material composition, cast iron is usually more brittle than cast steel.

If you need a durable material, then cast steel may be a better choice. However, if you need a harder material, then cast iron may be a better fit for your project.

Chemical Composition

The different compositions of cast iron and cast steel also give each material different properties.

For example, cast iron typically contains more carbon than cast steel. As a result, cast iron is usually more brittle than cast steel.

Cast steel contains less carbon than cast iron. As a result, cast steel is usually tougher and more ductile than cast iron.

Melting Point

Cast iron usually has a lower melting point than cast steel.

Cast iron has a melting point of about 1150 degrees Celsius, while cast steel has a melting point of about 1380 degrees Celsius. So cast iron is easier to cast.

Surface Brightness

The surface brightness of cast iron is duller than that of cast steel.

The main reason for this is that the carbon in cast iron forms pearlite, which is a dark phase that gives cast iron a darker color.

In contrast, the carbon in cast steel can be in the form of ferrite or austenite, both of which are brighter phases.

As a result, the surface of cast steel looks brighter than the surface of cast iron when viewed by the naked eye.

Sound

This is important when you are working with both materials.

Cast iron has a more dull “bang” sound when struck. Cast steel, on the other hand, has a higher “ping” sound.

The difference in sound is due to the different ways in which the molecules in each material vibrate.

Grain

Cast iron usually has larger particles than cast steel. Large grains give cast iron a granular texture. Shiny cast steel has smaller grains.

There is a direct relationship between the size of the grain and the strength of the material. The smaller the grain, the stronger the metal.

This is why cast steel is often used in construction projects. It has a small grain size, making it strong and durable.

Cast iron, on the other hand, has a large grain size. This makes it less strong than cast steel and more susceptible to corrosion.

Heat resistance

Cast iron is made by pouring molten iron into a mold, while cast steel is made by first melting the steel and then pouring it into the mold.

Cast iron can withstand high temperatures, making it ideal for use in high-temperature environments. On the other hand, cast steel is more resistant to high temperatures than cast iron.

This makes cast steel ideal for applications where high temperatures are a concern, such as in the aerospace industry.

Abrasion and wear resistance

Abrasion resistance and wear resistance are important factors to consider when selecting materials for your project.

Cast iron typically has better wear resistance than cast steel because of the higher carbon content in cast iron. The higher the carbon content, the harder the material becomes. This hardness gives cast iron better wear resistance.

However, the high hardness also makes cast iron more brittle. This means it is more likely to crack and fracture under heavy loads.

Cast steel, on the other hand, is less likely to crack or fracture because it is less brittle than cast iron. Cast steel has a lower carbon content, and the lower carbon content makes the material more ductile, which gives it better toughness.

Therefore, if you are looking for a material with good wear resistance and good toughness (impact resistance), then cast steel is also a solid choice.

Corrosion Resistance

Cast iron is more resistant to corrosion than cast steel.

This is due to the fact that cast iron contains more carbon than cast steel. The higher the carbon content, the more corrosion resistant the metal will be.

However, not all cast iron is more resistant to corrosion than cast steel, and corrosion resistance can only be achieved by adding a special proportion of ingredients that can make it resistant to corrosion.

Strength

Strength is one of the most important characteristics to consider when measuring your project. So, which is stronger, cast iron or cast steel? The answer may surprise you.

Cast iron is actually much weaker than cast steel. The reason for this is that cast iron is very brittle and its molecules are not as tightly bound together as steel.

This means that when force is applied to cast iron, it is more likely to break or shatter than steel. If you are looking for a material that can withstand great forces, then cast steel is the one for you.

In fact, cast iron is about 50% weaker than cast steel in terms of strength.

However, this does not mean that it should be avoided for all projects. For example: If your project does not require a lot of strength, or if it will be in a protected environment, cast iron may be the best choice.

Hardness, Toughness & Ductility

Cast iron is harder, but more brittle, which means it tends to break under impact or pressure. Cast steel, on the other hand, is ductile and malleable, which means it can bend rather than break.

This makes cast steel ideal for applications where impact or pressure is a problem, such as automotive parts or construction equipment.

Weight

Cast iron is significantly heavier than cast steel.

This is because cast iron contains more carbon. The extra carbon makes cast iron more brittle, which can be a disadvantage if your project requires a lot of strength.

However, the extra carbon also makes cast iron better at conducting heat, which would be an advantage if your project requires heat resistance.

Cast steel is lighter than cast iron because it contains less carbon. This makes cast steel stronger than cast iron and better suited for projects that require a lot of strength.

However, the lower carbon content also means that cast steel does not conduct heat as well as cast iron.

Machinability

Cast iron typically contains more carbon than cast steel, which makes it harder and more brittle.

This means that it is more difficult to machine than cast steel. It is also more likely to crack during machining.

Cast steel, on the other hand, has a lower carbon content, which makes it softer and more ductile.

This makes it easier to machine and less likely to crack during processing.

Weldability

Weldability is the ability of a material to be joined together by welding. Both cast iron and cast steel have good weldability, but there are some differences.

Due to the high carbon content of cast iron, it is more brittle than cast steel, so it is less weldable. However, cast iron can be welded with mild steel electrodes.

Cast steel it is much easier to weld. It can be welded with high carbon electrodes.

Casting Properties

Cast iron usually has good casting properties. Cast iron can be cast into shapes with more intricate details than cast steel.

This is due to the fact that cast iron has a lower melting point than cast steel. Cast iron is also easier to cast because it contains less pure iron.

Heat Treatment

Heat Treatment is a process of heating and cooling metal to change its physical and mechanical properties without changing its shape.

The most common purpose of heat treatment is to harden or soften the material. Other purposes include restoring ductility, improving machinability, increasing strength, or creating a more uniform microstructure.

Cast iron can be heat-treated to increase its strength and hardness. Cast steel can also be heat-treated to increase its strength and hardness.

However, cast steel can only be heat treated under certain temperature conditions.

Price

The price of cast iron and cast steel varies depending on the type of project. For example, for a small project, such as repairing a water main leak, cast iron would be more economical and practical.

A larger project, such as building a bridge or constructing a tall building, would require cast steel because it is stronger.

When it comes to price, cast iron is usually cheaper than cast steel. The main reason cast iron is cheaper than cast steel is that it contains less pure iron and therefore requires less machining.

The lower production costs and the fact that cast iron is easily recycled make cast iron a more economical choice for many applications.

Applications

Both cast iron and cast steel have a wide range of applications. However, because of their different properties, they are often used for different purposes.

Cast iron is commonly used in the construction industry for applications such as drainage pipes and manhole covers. It is also used in the automotive industry for engine blocks and cylinder heads.

Cast steel is also commonly used in the construction and automotive industries. It is often used for structural components, as well as engine components such as crankshafts and camshafts.

Cast iron is often used in projects where weight is a key consideration.

Cast steel is often used in construction projects or for products that need to be very strong and durable.

Conclusion

In summary, the main differences between cast iron and cast steel are

-Cast iron is more brittle and less ductile than cast steel.

-Cast iron is usually heavier than cast steel.

-Cast iron is more difficult to machine than cast steel.

-Cast iron has good casting properties, but cast steel has better welding properties.

-Cast iron can be heat treated to improve strength and hardness, but cast steel can only be heat treated at a certain temperature.

-When it comes to price, cast iron is usually cheaper than cast steel.

If you need a material that can be cast into very complex shapes, then cast iron is probably the better choice. If you need a material that is very strong and durable, then cast steel may be a better choice.

If cost is a key consideration, then cast iron is usually the more economical choice. Ultimately, it comes down to what you need and what your preferences are.

Regardless of which material you choose, you can be sure that both cast iron and cast steel have a wide range of applications and are good choices for projects where strength, durability and weight are important considerations.