A company that specializes in manufacturing cutting tools wants to produce high performance steel cutting tools using a steel with a carbon content of 0.8 wt%. They plan to use a series of heat treatment processes, including austenitizing, quenching, and tempering, to achieve the desired properties. A Time-Temperature-Transformation (TTT) diagram for iron-iron carbide is available in Fig. 2 to help guide the heat treatment process.

Temperature (C) 1600 1538C 1493C 1400 1394C Y+L 1200 y. Austenite 2.14 1000 912C 800a 600 0.76 0.022 a, Ferrite 400 0 1 2 (Fe) 10 Composition (at% C) 15 20 27 25 L 1147C 4.30 a + Fe3C Y+ Fe3C 727C 2500 2000 1500 Cementite (Fe3C). 1000 4 5 6 6.70 Composition (wt% C) Figure 1: Iron-iron carbide phase diagram. Temperature (F)