Answer:
a) The proeutectoid phase is known like cementite and its chemical formula is Fe₃C
b) The kilograms of total ferrite and is 0.8311 kg
The kilograms of total cementite is 0.1689 kg
c) The kilograms of total cementite is 0.9343 kg
Explanation:
Given:
1 kg of austenite
1.15 wt% C
Cooled to below 727°C
Questions:
a) What is the proeutectoid phase?
b) How many kilograms each of total ferrite and cementite form, Wf = ?, Wc = ?
c) How many kilograms each of pearlite and the proeutectoid phase form, Wp = ?
d) Schematically sketch and label the resulting microstructure
a) The proeutectoid phase is known like cementite and its chemical formula is Fe₃C
b) To get the mass of the total ferrite form:
[tex]W_{f} =\frac{C_{cementite}-C_{2} }{C_{cementite}-C_{1} }[/tex]
Here,
Ccementite = composition of cementite = 6.7 wt%
C₁ = composition of phase 1 = 0.022 wt%
C₂ = composition of alloy = 1.15 wt%
Substituting values:
[tex]W_{f} =\frac{6.7-1.15}{6.7-0.022} =0.8311kg[/tex]
To get the mass of the total cementite:
[tex]W_{c} =\frac{C_{2}-C_{1}}{C_{cementite}-C_{1} } =\frac{1.15-0.022}{6.7-0.022} =0.1689kg[/tex]
c) The mass of pearlite:
[tex]W_{p} =\frac{6.7-1.15}{5.94} =0.9343kg[/tex]
d) In the diagram you can see the different compositions (pearlite, proeutectoid cementite, ferrite, eutectoid cementite)
A) The proeutectoid phase is; Cementite(Fe₃C).
B) The kilograms each of total ferrite and cementite form are;
Mass of ferrite = 0.83 kg
Mass of cementite = 0.17 kg
C) The kilograms each of total pearlite and the proeutectoid phase form are;
Mass of pearlite = 0.93 kg
Mass of proeutectoid phase form = 0.07 Kg
D) Resulting microstructure has been sketched and attached
A) We are told that austenite contains 1.15 wt% C. Now, this composition is greater than eutectoid that has a composition of 0.76 wt % C. Thus, we can say that the proeutectoid phase is Cementite(Fe₃C).
B) By use of lever rule of lever rule expression, we can say that;
W_ferrite = (C_Fe₃C - C₀)/(C_Fe₃C - C_α)
Where;
C_Fe₃C is composition of carbon by wt% in cementite = 6.7%
In phase diagram of cementite, the composition of phase 1 is; C_α = 0.022%
We are given C₀ = 1.15 wt% C
Thus;
W_ferrite = (6.7 - 1.15)/(6.7 - 0.022)
W_ferrite = 0.83
Since mass of alloy is 1 kg, then mass of ferrite = 1 × 0.83
Mass of ferrite = 0.83 kg
Similarly;
W_cementite = (C₀ - C_α)/(C_Fe₃C - C_α)
W_cementite = (1.15 - 0.022)/(6.7 - 0.022)
W_cementite = 0.17
Since mass of alloy is 1 kg, then mass of ferrite = 1 × 0.17
Mass of cementite = 0.17 kg
C) Similar to the mass equations we have in answer B above, we can do so for pearlite and proeutectoid phase form.
For Pearlite;
W_pearlite = (6.7 - 1.15)/(6.7 - 0.76)
W_pearlite = 0.93
Since mass of alloy is 1 kg, then mass of ferrite = 1 × 0.93
Mass of pearlite = 0.93 kg
For the proeutectoid phase form;
mass of proeutectoid phase form = 1 - mass of pearlite
⇒ 1 - 0.93
mass of proeutectoid phase form = 0.07 kg
D) The sketch of the resulting microstructure has been attached.
Read more at; https://brainly.com/question/10053141
