Determine the amount of gamma and alpha phases in a 10-kg, 1060 steel casting as it is being cooled to the following temperatures: (a) 900°C; (b) 728°C; and (c) 726°C.

Given that

Mass, m=10 kg

a)

At 900°C

From iron carbon diagram

Percentage of alpha phase = 0 %

Percentage of gamma phase = 100 %

b)

At 728°C

From iron carbon diagram

Percentage of alpha phase = 23 %

Percentage of gamma phase = 77 %

c)

At 726°C

From iron carbon diagram

Percentage of alpha phase = 91 %

Percentage of gamma phase = 9 %