One of our customers asked me which is better, cast iron or cast steel. I have to say, nobody does it better. The question is which one is better for your product.

First, let's understand what cast iron and cast steel are.
Cast iron usually refers to gray cast iron, ductile iron and malleable cast iron. It is an iron casting with a carbon content higher than 2%.

Cast steel usually refers to ordinary carbon steel and alloy steel. It is a steel casting with a carbon content of less than 2%.

Therefore, the chemical composition and raw materials of cast iron and cast steel are not much different. However, there are many differences in their physical properties.

Advantages and disadvantages of cast iron.
Good casting properties of gray cast iron are: good vibration damping, good wear resistance, good machinability and low notch sensitivity. However, it has low tensile strength and elongation. Therefore, it can only produce some metal parts with low physical requirements. Protective cover, cover, oil pan, hand wheel, shelf, bottom plate, hammer, small handle, base, shelf, box, knife, bed, bearing seat, workbench, wheel, cover plate, pump, valve, pipe, Flywheel, motor block, etc. As for higher grades, gray cast iron can withstand greater loads and some degree of tightness or corrosion resistance. This allows for some of the more important castings such as cylinders, gears, bases, flywheels, beds, cylinder blocks, cylinder liners, pistons, gearboxes, brake wheels, coupling plates, medium pressure valves, etc.

Ductile iron and malleable iron have high strength, ductility and heat resistance and toughness. Therefore, the application range is wider, and in some cases, it can replace carbon steel. However, its production technology is high. The production process is more complicated. This makes the production cost higher than ordinary gray cast iron and cast steel. Therefore, the casting defects of ductile iron are more. There are many areas where ductile iron is used, such as pressure piping and fittings, automotive applications, agriculture, road and construction applications, and general engineering applications.

Advantages and disadvantages of cast steel.
The main advantage of cast steel is design flexibility. Casting designers have the greatest freedom of design choice. This allows complex shapes and hollow section parts.
Cast steel offers the flexibility and greatest variability of metallurgical manufacturing. Different chemical compositions and controls can be selected to suit different requirements of different projects. This provides different heat treatment options across a greater range of mechanical properties and properties. Also provides good weldability and machinability.
Cast steel is an isotropic material that can be made into steel castings with high overall structural strength. This increases the reliability of the project. Combined with design and weight, advantages such as short lead times, price and economy give cast steel a competitive advantage.
Steel castings have a wider range of weights. The weight is extremely small, and precision castings with only a few tens of grams can be invested. The weight of large steel castings can reach several tons, tens of tons or hundreds of tons.
Steel castings can be used in a variety of working conditions. Its mechanical properties are superior to any other cast alloys, as well as various high-alloy steels for special purposes. To withstand high tensile stresses or dynamic loads on components, it is important to consider pressure vessel castings. In low temperature or high temperature, large and important part load key parts should be preferentially used steel castings.

However, the shock absorption, wear resistance and fluidity of cast steel are relatively poor. Compared with cast iron, casting performance is poor. In addition, the cost is higher than ordinary cast iron.

So, when it comes to cast iron and cast steel, they each have pros and cons. One of the two should be selected based on the application and its physical characteristics.