Temperature (°C) 800 700 600 A 500 400 A 300 A Eutectoid temperature 1400 P B 1200 1000 800 600 M(start) 50% 200 M+A 400 00 M(50%) M(90%) 100 ° 10-1 1 10 102 103 104 105 Time (s) 200 Temperature (°F)