Pre Exam

Front

Which of the following correctly ranks the three types of ferrous alloys by their carbon content, from lowest (<0.008. wt% C) to highest (2.14 - 6.70 wt% C)?
Options:
iron, cast iron, steel
steel, cast iron, iron
cast iron, iron, steel
iron, steel, cast iron

Back

iron, steel, cast iron

Front

When cooled slowly, transformations near the melting temperature tend to yield ___ grains due to the formation of___ nucleation sites followed by ____ grain growth.

Back

coarse…few…slow

Front

In the Pb-Sn phase diagram, how many degrees of freedom are there in the solid alpha single phase region and at the invariant points?

Back

2.0

Front

For a solid-state transformation that obeys the Avrami equation, the parameter n has been determined to have a value of 1.5. The reaction takes 125 seconds to reach 30% completion. What is the total time in seconds for the transformation to reach 95% completion?

Back

516

Front

Based on the standard EMF series and your knowledge of half-reactions, determine the cell potential and spontaneity of a cell that consists of a pure cobalt electrode in a solution of Co2+ ions; the other half is a lead electrode immersed in a Pb2+ solution. Pb2+ + 2e- —-> Pb -0.126 Sn2+ + 2e- —-> Sn -0.136 Ni2+ + 2e- —-> Ni -0.25 Co2+ + 2e- —-> Co -0.277

Back

+0.151, spontaneous

Front

What best describes the thermodynamic condition that must be met for a state of equilibrium to exist?

Back

Minimized Free Energy

Front

For the solidification of pure gold, calculate the critical radius (r*) and the activation of free energy (AG"). Assume homogeneous nucleation conditions. The values of the latent heat of fusion and the surface free energy are -1.16x10^9° J/m° and 0.132 J/m², respectively. The degree of supercooling is 230 K and the melting point of gold is 1064 °C.

Back

1.3 nm and 9.6x10-19 J/m²

Front

For the solidification of pure gold, calculate the critical radius (r*) and the activation of free energy (AG"). Assume homogeneous nucleation conditions. The values of the latent heat of fusion and the surface free energy are -1.16x10^9° J/m° and 0.132 J/m², respectively. The degree of supercooling is 475 K and the melting point of gold is 1064 °C.

Back

0.6 nm and 2.3×10-19 J/m²

Front

Identify the appropriate type of corrosion for the following situation: A form of intergranular corrosion which occurs in the heat affected zones of stainless steel welds through the formation of Cr23C, precipitates.

Back

Sensitization

Front

There are several techniques available for suppressing and controlling corrosion. Which of the following would be most suitable from economic and engineering perspectives for protecting an underground storage tank? Institute cleaning and inspection regime, Minimize temperature of tank, Coat with noble metal (i.e. gold), Cathodic protection

Back

Cathodic protection