phase transformation reaction

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  1. 1. PRESENTED BY ABHIJEET CHOUDHARI
  2. 2. Three Phase Reactions Peritectic, at 1492C, with low % of Carbon in alloys. (almost no engineering importance). Eutectic, at 1147C, with 4.3% Carbon, alloys called cast irons. Eutectoid, at 727C with eutectoid composition of 0.8% Carbon, having two- phase mixture (ferrite & cementite). They are steels.
  3. 3. Eutectic, Eutectoid, & Peritectic: Peritectic - liquid and one solid phase transform to a 2nd. solid phase Solid1 + Liquid Solid2 + L Eutectic - liquid transforms to two solid phases L + Eutectoid one solid phase transforms to two other solid phases Solid1 Solid2 + Solid3 + Fe3C +
  4. 4. Eutectoid reaction Redistribution of carbon by diffusion Austenite 0.76 wt% C Ferrite - 0.022 wt% C Cementite - 6.70 wt% C Pearlitey+ Fe3C
  5. 5. Simplified Iron-Carbon phase diagram austenite pearlite (mixture of ferrite & cementite)
  6. 6. Nucleation & growth of pearlite
  7. 7. Schematic picture of the formation and growth of pearlite
  8. 8. Ferrite () Cementite
  9. 9. Principal phases of steel and their Characteristics
  10. 10. SUMMARY Basically in Eutectoid reactions, a single solid converts into two different solids while cooling at Eutectoid temperature. eg: Fe-C, Cu-Sn, Cu-Al, Zn-Al, Al-Mn, etc.
  11. 11. ANY QUARIES.......
  12. 12. Referances.... Material science & Metallurgy By V.D. Kodgire, S.V. Kodgire. Google, Wekipedia.
  13. 13. THANK YOU!