First Step: Identify the Iron. It all starts with this little "slug"
Lets say that we are in a Laboratory and we happen upon a little piece of iron that looks like this...
How to identify?
-Normal circumstances would tell you what kind of iron it was with some sort of sample ID
EX 03222023222202 would tell us the sample was today at 1020PM and it is a ductile iron of the 2202 grade...which basically tells us the hardness range we are looking for.
However that is hardly enough...we must uncover more about this little slug.
Second Step: Hardness
If you are lucky your lab will have a camera used specifically for checking hardness.
Check for calibration...there should be a block around labeled with the correct measurement.
POLISH that surface until it appears like a mirror and then give it an etch.
Step 4: Examine under the microscope
After a proper polish under 100X the surface should appear something like this....
The nodularity of the second photo is much better. So a good polish is key to a good sample.
|Better polish...worse picture.|
|poor polish however nodules still present|