The temperature required for full annealing in hypereutectoid steel is
A. 30° C to 50° C above upper critical temperature
B. 30° C to 50° C below upper critical temperature
C. 30° C to 50° C above lower critical temperature
D. 30° C to 50° C below lower critical temperature
Answer: Option C
Solution(By Examveda Team)
Full annealing is the process of slowly raising the temperature about 50 ºC (122 ºF) above the Austenitic temperature line A3 or line ACM in the case of Hypoeutectoid steels (steels with < 0.77% Carbon) and 50 ºC (122 ºF) into the Austenite-Cementite region in the case of Hypereutectoid steels (steels with > 0.77% Carbon).This Question Belongs to Mechanical Engineering >> Engineering Materials
C is correct
Option A is correct
Correct answer is option c
Temp required for hypoetuctiod < 0.8 steel in full annealing = above upper critical temperature
Temp required for hyperetuctiod >0.8 steel in full annealing = above lower critical temperature
correct answer is A