Answer:
a) The phase before eutectoid is commonly referred to as cementite, with the chemical formula Fe₃C.
b) The total mass of ferrite obtained is 0.8311 kg.
The total cementite mass equals 0.1689 kg.
c) The total cementite mass accounts for 0.9343 kg.
Explanation:
Provided:
1 kg of austenite
a carbon content of 1.15 wt%
Cooled below 727°C
Questions:
a) Identify the proeutectoid phase.
b) Calculate the mass of total ferrite and cementite, Wf =?, Wc =?
c) Determine the mass of both pearlite and the proeutectoid phase, Wp =?
d) Create a schematic to illustrate the resulting microstructure.
a) The proeutectoid phase is referred to as cementite with the formula Fe₃C.
b) To find the total mass of formed ferrite:

With:
Ccementite = composition of cementite = 6.7 wt%
C₁ = composition of phase 1 = 0.022 wt%
C₂ = overall composition = 1.15 wt%
Inserting the values yields:

For the total mass of cementite:

c) The mass of pearlite:

d) The diagram illustrates the different compositions: (pearlite, proeutectoid cementite, ferrite, eutectoid cementite)