What simple solution is there if such a cheap, low quality steel must be used ?
Think about you answer, and then proceed.
|
The machinability of this low carbon steel rod (shown here
at 200X after a Nital etch) was poor because of the saft, decarburized
surface. The microstructure consists of ferrite plus spheroidized
pearlite (which isn't resolved here). The specimen was probably
cold rolled and then process annealed (i.e., recrystallized by heating
just below the eutectoid temperature). What simple solution is there if such a cheap, low quality steel must be used ? Think about you answer, and then proceed. |
| Remedy: use cold rolled or cold drawn low
carbon steel, which will have a more uniform hardness and more easily
broken chips in spite of any
decarburization.
Now, go on to Specimen 3. |