Answer:
The Ranking from
Hardest to softest is as follows :
0.80 wt% C with fine pearlite.
0.80 wt% C with spheroidite
0.25 wt% C with coarse pearlite
0.25 wt% C with spheroidite
Explanation:
To find - Rank the following iron-carbon alloys and associated microstructures from the hardest to the softest. Justify this ranking.
Solution -
Ranking is as follows :
(d) 0.80 wt% C with fine pearlite.
(b) 0.80 wt% C with spheroidite
(a) 0.25 wt% C with coarse pearlite
(c) 0 25 wt% C with spheroidite
Justification -
For some wt% C,
Fine pearlite is stronger than spheroidite
and
Coarse pearlite is stronger than spheroidite.
Now,
Due to carbon content,
0.80 wt% C with spheroidite is stronger than 0.25 wt% C with coarse pearlite.
So,
The Ranking from
Hardest to softest is as follows :
0.80 wt% C with fine pearlite.
0.80 wt% C with spheroidite
0.25 wt% C with coarse pearlite
0.25 wt% C with spheroidite