Question 1

Which of these materials is susceptible to 885º F embrittlement?

Accepted Answer

A)  400 Series SS 
B)  Duplex SS 
C)  5Cr-1Mo 
D)  Both A and B

Question 2

Cracking can occur at low caustic levels if a concentrating mechanism is present. In such cases, caustic concentrations of ________ ppm are sufficient to cause cracking.

Accepted Answer

A)  50-100 
B)  100-150 
C)  150-200 
D)  200-250

Question 3

It is generally accepted that stresses approaching _________ are required for SCC to occur so that thermal stress relief is effective in preventing caustic SCC.

Accepted Answer

A)  MAWP 
B)  Yield 
C)  Creep range 
D)  Critical

Question 4

Low creep ductility is __________ severe in high tensile strength materials and welds.

Accepted Answer

A)  More 
B)  Less 
C)  Usually 
D)  Not

Question 5

Most brittle failures occur:

Accepted Answer

A)  Below the impact transition temperature. 
B)  On thinner materials. 
C)  On "clean" steel. 
D)  While in operation at elevated temperatures.

Question 6

Oxygen and iron in the wash water injected into reactor effluent can lead to __________ corrosion and fouling.

Accepted Answer

A)  Increased 
B)  Decreased 
C)  Substantial 
D)  Minimal

Question 7

_________ is a mechanical form of degradation that occurs when a component is exposed to cyclical stresses for an extended period, often resulting in sudden, unexpected failure.

Accepted Answer

A)  Stress fatigue 
B)  Mechanical fatigue 
C)  Thermal fatigue 
D)  Cyclic fatigue

Question 8

Susceptibility to hydrogen stress cracking __________ with __________ hardness.

Accepted Answer

A)  Increases, increasing 
B)  Decreases, increasing 
C)  Decreases, Decreasing 
D)  Both A and C

Question 9

To prevent carburization, select alloys with a strong surface oxide or sulfide film former such as ________.

Accepted Answer

A)  Silicon 
B)  Molybdenum 
C)  Aluminum 
D)  Both A and C

Question 10

_________ is a selective corrosion mechanism in which one or more constituents of an alloy are preferentially attacked leaving a lower density often porous structure.

Accepted Answer

A)  Phenol corrosion 
B)  Dealloying 
C)  Carburization 
D)  Preferentially weld attack

Question 11

For 5Cr-0.5Mo, what is the threshold temperature for creep?

Accepted Answer

A)  500º F 
B)  800º F 
C)  600º F 
D)  700º F

Question 12

The most common method used for monitoring underground structures is measuring the structure to soil ______ using dedicated reference electrodes near the structure.

Accepted Answer

A)  Resistivity 
B)  Corrosiveness 
C)  Potential 
D)  Electrolyte

Question 13

____________ is often found in piping and equipment that handles caustic, including H₂S and mercaptan removal units, as well as equipment that uses caustic for neutralization in sulfuric acid and HF acid units.

Accepted Answer

A)  Carburization 
B)  Sulfide corrosion 
C)  Caustic embrittlement 
D)  Hydrogen cracking

Question 14

When caustic stress corrosion cracking is a concern, steam out of _________ carbon steel piping and equipment should be avoided.

Accepted Answer

A)  PWHT 
B)  Non-PWHT 
C)  Ferritic 
D)  Hardened

Question 15

SSC generally occurs below about ________.

Accepted Answer

A)  225º F 
B)  200º F 
C)  180º F 
D)  150º F

Question 16

When connected to a more anodic material, titanium may suffer severe __________.

Accepted Answer

A)  Corrosion 
B)  Hydriding 
C)  Stress 
D)  Notch toughness

Question 17

Vessels constructed after December, 1987 are subject to the requirements of ________ of ASME Section VIII, Division 1.

Accepted Answer

A)  UW-26 
B)  UG-31 
C)  UB-54 
D)  UCS-66

Question 18

The best method to inspect for SCC is ____.

Accepted Answer

A)  WFMT 
B)  UT Shear wave 
C)  AET 
D)  All of the above

Question 19

Stainless steels with sigma can normally withstand normal operating stresses but upon cooling to temperatures below _______ may show a complete lack of fracture toughness as measured by a Charpy impact test.

Accepted Answer

A)  800º F 
B)  600º F 
C)  500º F 
D)  400º F

Question 20

Proper application of ________ will control but not eliminate microbes that cause MIC so that continued treatment is necessary.

Accepted Answer

A)  Ozone 
B)  Caustic 
C)  Biocides 
D)  None of the above

Exam 1: Corrosion and Materials