Hot rolling is carried out in which region?

Hot rolling is carried out in which region?

• A. Below the lower transformation temperature
• B. In the fully austenitic region
• C. In the austenite/ferrite region
• D. Between 723 C and 912 C

Answer: (B)

Hot rolling requires heating the metal until its microstructure is a single, ductile phase so it can deform easily. For steels, this means being in the fully austenitic region, where the structure is all austenite. In this state the material can undergo large plastic deformation with lower flow stress and without forming brittle phases during deformation. The other temperature ranges describe ferrite/pearlite mixtures or colder working conditions, which are not suited to hot rolling. Therefore, hot rolling is carried out in the fully austenitic region.

Hot rolling requires heating the metal until its microstructure is a single, ductile phase so it can deform easily. For steels, this means being in the fully austenitic region, where the structure is all austenite. In this state the material can undergo large plastic deformation with lower flow stress and without forming brittle phases during deformation. The other temperature ranges describe ferrite/pearlite mixtures or colder working conditions, which are not suited to hot rolling. Therefore, hot rolling is carried out in the fully austenitic region.