Collection of exam questions

Pagina 1

ELENCO DOMANDE D’ESAME Le risposte corrette sono state volutamente riportate in fondo al documento, cosicché sia data al lettore la possibilità di ragionare liberamente. Tutte le domande provengono da temi d’esame e non sono state modificate. A causa della scarsa qualità delle fonti primarie, è impossibile garantire la fedeltà assoluta rispetto alle originali delle domande che comprendano immagini. Si consiglia di consultare questo pdf al termine del corso. L’ordine delle domande è casuale. 1) Why N effect in solution strengthening is higher than that of C: a. Because N lattice distortion is lower b. Because C increases cross sleep c. Because N is more effective in lattice distortion and reduce cross slip 2) The Orowan process takes place if: a. The precipitates can be cut by dislocations moving through them b. The dislocation can bypass the particle by changing its slip plane c. If the particles are impenetrable by the dislocations 3) To increase pitting corrosion resistance the better solution is: a. Increase Mo content b. Decrease Cr content c. Increase C content 4) Intergranular corrosion stainless steel may be avoided: a. Welding it b. Solubilizing it c. Immersing it in sea water 5) Duplex stainless steel: a. Are martensitic b. Have higher resistance to SCC than austenitic c. Have lower mechanical properties than ferritic 6) How IF steels strengthening mechanism works? a. Solute atoms replace atoms of the solvent material in the crystal lattice. Since the solute and solvent atoms are different sizes, they interrupt the regularity of the crystal lattice. Dislocations cannot easily move around this interruption. b. Alloying elements exceeding the solubility limit within the steel lattice matrix segregate at the grain boundaries. The finer are these grain boundaries…