Spheroidite and tempered martensite are fabricated by very different heat treating routes. Spheroidite is made by annealing coarse pearlite for an extended period of time (?24 h) near the eutectoid temperature, while tempered martensite is formed by rapidly quenching austenite, and then heating the material to ? 400°C for 1 hour. a) Sketch the microstructures for spheroidite and tempered martensite based on the processing routes discussed above. Label the phases present. b) Which material will exhibit the greater hardness? Briefly explain.