How to distinguish cast iron from metal?

Cast iron is a metal formed from an alloy of iron and carbon. This material has good casting qualities and is cheap. Typically, cast iron is used in the engineering industry. In addition, pig iron is the main raw material for steel smelting. Iron ore, fluxes and fuels are used to produce this material.

Often times, a crack, fracture or chipping can be found in metal structures or parts. In this case, there is a need for repair welding work. In order to properly carry out such a repair, you need to know what kind of metals you are dealing with – steel or cast iron. How to distinguish cast iron from metal?

Before proceeding with the study of a surface that needs repair, you should prepare:

* Drill.
* Grinding machine.
* Small file or file.

Determination procedure

1. First of all, it is necessary to find a place on the surface of the part that is not striking and several times to walk over it with a small file or a needle file. As a result, small sawdust forms on the surface of the metal (or cast iron). They should be taken and rubbed between your fingers. If you are dealing with cast iron, then the fingers will be painted in the characteristic black graphite color. For greater clarity, you can take some sawdust and place them between two sheets of white paper and lightly rub the sheets against each other. If you are dealing with steel, the paper will remain clean.
2. You can also determine if it is steel in front of you or cast iron using a grinder. To do this, you should prepare in advance two parts, the composition of which you know for sure, made of steel and cast iron. Now you need to turn on the grinder and start up sparks from them one by one. Having compared the shape and color of the sparks formed, it is required to do the same with the part, the composition of which must be determined. The conclusion can be drawn based on the greatest analogy with samples.
3. Sparks generated during the grinding of steel will fly tangentially along the circumference of the grinding wheel. If the metal contains carbon, that is, you are dealing with cast iron, then the particles that have heated up during the grinding process, flying into the air and in contact with it, will oxidize – thus, the carbon goes into carbon dioxide. It should also be noted that when the grinding wheel comes into contact with the cast-iron surface, a lot of sparks, rather short in length, are always formed. In addition, the sparks produced when grinding cast iron have a bright straw color.
4. To determine in the following way, you need to take a drill and insert a drill with a small diameter into it. You should find an inconspicuous place on the part, turn on the drill and drill a little. Since there are significant differences in drilling cast iron parts from drilling steel parts, it is recommended that you take two parts made of steel and cast iron and try to drill them. In the process of drilling cast iron, practically no chips are formed. And if they have formed, they will have very small sizes, and when rubbed between the fingers, the cast iron shavings easily turn into dust. Steel shavings have a curled shape and resemble wire. In addition, steel shavings are difficult to break with your fingers.
5. A lathe can also be used in the same way – the cast iron shavings will look like coarse dust.