The questions in the following question all pertain to the iron-carbon phase diagram, shown below. Composition (at% C) 10 15 0 5 20 25 1600 1538C - 1493C L 1400 8 2500 1394C 7+L 1200 1147C 2.14 4.30 y, Austenite 2000 1000 Temperature (F) 912C y + Fezc 800 1500 a + Y 727C 0.76 0.022 600 a, Ferrite a + Fezc Cementite (Fe3C) 1000 400 0 (Fe) 6 6.70 3 4 Composition (wt% C) a. What invariant reaction and phase transformation is occurring when cooling from 1148C in a 4.3wt% carbon steel alloy? b. For a 1kg sample of 0.50 wt% carbon steel at 726C, what will be the mass, in grams, of a ferrite? c. For a 1kg sample of steel at 726C, what would be the maximum mass of carbon, in grams, that could dissolve as a solid solution? d. The mass fractions of total ferrite and total cementite in an iron-carbon alloy at 726C are 0.88 and 0.12, respectively. Is this a hypoeutectoid or hypereutectoid alloy? Why