microstructure of medium carbon steel

Medium Carbon Steel ( Fe 0.3wt%C )

0.3wt% carbon steel.
This steel has been normalised and has a microstructure of ferrite and pearlite. It can be compared to the normalised 0.1wt% carbon steel, which has a lower amount of pearlite. The hard pearlite eutectoid gives the steel higher strength, but lower ductility.
These are therefore important structural steels (beams and girders) for engineering purposes.

Medium Carbon Steel ( Fe 0.4wt%C )

0.4wt% carbon steel

This has a very similar structure to the normalised 0.3wt% carbon steel. The higher carbon content gives more pearlite eutectoid, with higher strength and lower ductility.

Medium Carbon Steel ( Fe 0.5wt%C )

This 0.5wt% carbon steel has been quenched from high temperature (900°C) as part of the quench and temper heat treatment. The microstructure developed is martensitic, and although this refines the grain size this also makes the steel very hard and brittle. Tempering is now required to reduce the brittleness.


click here .... :
http://pwatlas.mt.umist.ac.uk/internetmicroscope/micrographs/microstructures/more-metals/steel/medium-carbon-steel/fe-0.3-normalised.html



http://pwatlas.mt.umist.ac.uk/internetmicroscope/micrographs/microstructures/more-metals/steel/medium-carbon-steel/fe-0.4-normalised.html


http://pwatlas.mt.umist.ac.uk/internetmicroscope/micrographs/microstructures/more-metals/steel/medium-carbon-steel/fe-0.5-quenched.html