a) How could a structure containing only ferrite and martensite be produced in a 1045 steel specimen? Illustrate on a TTT diagram.

b) Could you heat treat a 1045 steel specimen so that it contains only ferrite? Describe how this can be achieved, or explain why it cannot be done.

c) Does the transformation of austenite into ferrite begin at the austenite grain boundaries and propagate inward, or does it begin inside the grains and propagate outward toward the boundaries?