The diffusivity of C in -ferrite (BCC iron) and diffusivity of C in y-austenite (FCC iron) is given at two temperatures: Diffusivity [m/s] Temperature [C] Diffusivity [m/s] C in y-Fe 500 --- 900 1100 Answer the following: (2 marks each) 5.9 x 10-12 5.3 x 10-11 a) Calculate the activation energy of diffusion for C in -Fe. b) Calculate the activation energy of diffusion for C in y-Fe. C in -Fe 2.4 x 10 -12 1.7 x 10-10 c) Explain why the diffusivity of C in -Fe is higher than the diffusivity of C in y-Fe.