Chemical Composition of Cast Iron and Cast Steel
Why is it important to control the
chemical composition of metal castings?
The chemical components of metal castings including normal Carbon
(C), Silicon (Si), Manganese (Mn), Sulfur (S), Phosphorus (P), and
also including many alloy components, such as Chrome (Cr),
Molybdenum (Mo), Nickel (Ni), Copper (Cu) etc.
Different chemical components have different functions, so caused
the very different mechanical properties, such as increasing their
tensile strength, hardness, abrasive resistance and corrosion
resistance. This is why we need to consider the chemical
Chemical Composition of Cast Iron, Grey Iron and Ductile Iron
As for the alloy cast iron, the chemical composition, especially the
alloy content, is very important. There will be big risk or
malfunction if the alloy content can not meet the requirements.
As for normal grey iron and ductile iron, the chemical composition
is not important comparatively. The iron foundries could adjust the
compositions according to their experience as long as they could
meet the physical and mechanical requirements. However, by
principle, the Sulfur should be controlled in the reason range, too
much sulfur will cause fragile of iron castings.
Chemical Composition of Cast Steel, Carbon Steel and Alloy Steel
Chemical composition is very important for steel castings, as for
the most of steel castings, as long as the chemical composition is
in the required range, then their mechanical properties should be
qualified. Because most cast steel should meet some special
properties besides of tensile strength and elongation, so chemical
composition will be the most important inspection.
How to inspect the chemical composition of cast iron and cast
1. Chemical analysis method (chemical test method)
Suitable for both cast iron, cast steel and alloy steel materials.
The accuracy of result depends on the skill of laboratory
Shortcoming: Slow, so can not meet the requirements for inspection
before and during production. Our foundry normally used this method
to inspect the chemical composition of pig iron materials.
2. Chemical composition spectrometer
Suitable for both cast iron and cast steel, and also alloy steel.
The accuracy and speed are very high, so good for inspection during
Shortcoming: If some chemical elements are very high or very low,
then the result will not be accurate.