Name the microstructural products of a 4340 steel alloy spec

Name the microstructural products of a 4340 steel alloy specimens that are first completely transformed to austenite, then cooled to room temperature at the following rates: 0.005 degree C/s 0.05 degree C/s 0.5 degree C/s 5 degree C/s

Solution

(a) proeutectoid ferrite and pearlite form

(B) martensite, ferrite and bainite form

(C) martensite and bainite form

(D) martensite and bainite form