Explain why the specimens of high carbon steel, after being heated to 700○C and 960○C andthen quenched from that temperature, have di↵erent hardness. Indicate the di↵erences ofobtained microstructure of these specimens after quenching.

answer is given below

Explanation:

given data

temperature T1 = 700°C

temperature T2 = 960°C

solution

first at temperature 700°C  

proeutectoid ferrite + pearlite on cooling there is no Martensite   (proeutectoid ferrite + pearlite)

and

at temperature 960°C  

austenite on rapid cooling is formed Martensite in carbon steels

so that

on sudden quenching alot point defect arrest and Martensite is form due to the shear mechanism and this create a lot of dislocation

so that here harness is very high on this condition

b. check your rearview mirror

explanation: