Often, when detecting any defects in a part or structure made of metal: cracks, breaks, chips - there is a need for repair. Is it possible and how to carry out, for example, welding work? How do you know which metal you are dealing with? Is it cast iron or steel?
Necessary
- - Grinder,
- - drill,
- - a file or small file.
Instructions
Step 1
Find an unobtrusive spot on the part and go over the metal several times with a file or small file. Rub the resulting sawdust in your fingers. Ordinary cast iron will leave a characteristic graphite black color on the skin.
It will be even clearer if you rub the sawdust between sheets of white paper. Steel filings will not stain the paper.
Step 2
You can determine - cast iron in front of you or steel - empirically: by the color and shape of the spark.
Turn on the grinder and take two parts or blanks you know you know: steel and cast iron. Let sparks from them one by one and compare. After that, go over exactly the same detail in which you doubt. Draw your conclusion on the basis of the greatest analogy with the samples.
Sparks generated when grinding steel are tiny molten metal particles that fly tangentially to the circumference of the circle where it contacts the part.
In the presence of carbon in the metal, hot particles, in contact with air, are oxidized, carbon is converted into carbon dioxide. This produces very numerous short-beamed sparks.
Cast iron will have a bright straw color.
Step 3
Take a drill and insert a small diameter drill into it. Determine a secluded place on the detail and drill a little.
Firstly, the very process of drilling a cast iron part is different from drilling into steel. To get a better feel for the difference, make similar drills on cast iron and steel samples you know.
Secondly, when drilling cast iron, almost no chips are formed. And if it does, it is very short and it is easily rubbed into dust with your fingers. Steel shavings are twisted like wire, and you can't break it with your fingers.
You can also check the type of metal by processing on a lathe - for cast iron, the chips will be coarse dust.
