material science

these questions are on Phase diagrams, effects of elements in phasetransformation, properties and microstructures.

1. Write all transformations with concentrations and temperatures for Fe0.4%C (a) and Fe1%C (b). Draw schemes of microstructure after solidification and full process annealing for the first alloy (a) and after casting and spheroidization annealing for the second one (b). Determine mass fraction of structural features after heat treatment. Compare their potential properties and applications. (10) Compare "HB vs carbon content" dependences for water quenched and annealed carbon steels (draw the rves). Show approximate quenching temperatures in Fe-C phase diagram. Explain the effect of austenite grain size on the final mechanical properties of tempered steels. (4) 3. Explain Mn and Si effect on microstructure and properties of cast irons. (3) 4. Compare ductility of malleable and gray cast irons with strength of 350MPa. Use microstructure analysis to explain and draw microstructure schemes (5) 5. Compare properties of pre-quenched carbon steel (0.3%C) after tempering at 250C and 650C. Use microstructural analysis to explain the difference (5) 6. Explain influence of Ni and Co on the hardenability of steels. (3)