Question 1

Which API RP recommends programs to monitor small-bore piping, flange faces, blistering and HIC/SOHIC in HF alky units?

Accepted Answer

A)  574 
B)  751 
C)  571 
D)  980

Question 2

Hydrochloric acid corrosion is a general and localized corrosion and is very aggressive to most common materials of construction. Damage in refineries is often associated with dew point corrosion in which vapors containing _______ and hydrogen chloride condense from the overhead stream of a distillation, fractionation, or stripping tower.

Accepted Answer

A)  O₂ 
B)  O 
C)  H₂O 
D)  CO₂

Question 3

In fired heater tubes, dissimilar weld metal cracking forms primarily on the _______ of the material.

Accepted Answer

A)  Outside 
B)  Inside 
C)  Welds 
D)  All of the above

Question 4

Corrosion rates of the anode can be high if there is a _______ anode to cathode ratio.

Accepted Answer

A)  Large 
B)  Small 
C)  Severe 
D)  None of the above

Question 5

Stainless steels have higher coefficients of thermal expansion than carbon steel or low alloy steel or nickel based alloys and are more likely to see _________.

Accepted Answer

A)  Higher temperatures 
B)  Higher stresses 
C)  Higher pressure 
D)  None of the above

Question 6

Application of a post-fabrication stress relieving heat treatment of about ______ is a proven method of preventing carbonate cracking.

Accepted Answer

A)  1100º F 
B)  1150º F 
C)  1200º F 
D)  1250º F

Question 7

Thermal fatigue is caused by:

Accepted Answer

A)  Cyclic stresses that come from temperature variations. 
B)  Long term operation at elevated temperatures. 
C)  Excessive thermal growth. 
D)  Hours of physical activity during a hot summer day.

Question 8

Localized corrosion due to the concentration of caustic or alkaline salts that usually occurs under evaporative conditions is _________.

Accepted Answer

A)  Carbonate corrosion 
B)  Caustic corrosion 
C)  Alkaline corrosion 
D)  None of the above

Question 9

Conditions favoring carburization include a high gas phase carbon activity and _______ oxygen potential.

Accepted Answer

A)  Low 
B)  High 
C)  Negative 
D)  Positive

Question 10

With steam blanketing, failure occurs as a result of _________ in the tube from the internal steam pressure at the elevated temperature.

Accepted Answer

A)  Stress risers 
B)  Velocity 
C)  Hoop stress 
D)  Tensile strength

Question 11

With hydrofluoric acid corrosion, corrosion rates increase with _______ temperatures and ______ HF concentrations.

Accepted Answer

A)  Increasing, decreasing 
B)  Decreasing, increasing 
C)  Increasing, increasing 
D)  Decreasing, decreasing

Question 12

Ferritic stainless steels are usually not used in __________ applications.

Accepted Answer

A)  Non-pressure boundary 
B)  Pressure boundary 
C)  High temperature 
D)  Low temperature

Question 13

Naphthenic acid corrosion is most severe in _________ flow; in areas of high velocity or turbulence and in distillation towers where hot vapors condense to form liquid phase droplets.

Accepted Answer

A)  Single phase 
B)  Two phase 
C)  Three phase 
D)  Negative phase

Question 14

Sigma phase in welds can be minimized by controlling ferrite in the range of _________ for Type 347 SS.

Accepted Answer

A)  3%-5% 
B)  5%-7% 
C)  7%-9% 
D)  5%-9%

Question 15

________ usually occurs when a colder liquid contacts a warmer metal surface.

Accepted Answer

A)  Stress cracking 
B)  Thermal fatigue 
C)  Thermal shock 
D)  Stress shock

Question 16

With Cl SCC, ________ levels of chloride ________ the likelihood of cracking.

Accepted Answer

A)  Decreasing, Increases 
B)  Increasing, Decreases 
C)  Increasing, Increases 
D)  Increasing, Eliminates

Question 17

Susceptibility to sulfidation is determined by the _________ of the material.

Accepted Answer

A)  Corrosion resistance 
B)  Tensile strength 
C)  Chemical composition 
D)  Yield strength

Question 18

Dew point corrosion can occur if the metal temperature is below the dew point. The dew point of sulfuric acid is __________.

Accepted Answer

A)  280º F 
B)  220º F 
C)  310º F 
D)  190º F

Question 19

________ is a form of carbon that may promote carburization, particularly during decoke cycles where temperatures exceed the normal operating temperatures.

Accepted Answer

A)  Carbonic acid 
B)  Coke 
C)  Crude oil 
D)  None of the above

Question 20

What standard refers to Risk-Based-Inspection?

Accepted Answer

A)  RP 581 
B)  RP 579 
C)  RP 588 
D)  RP 568

Exam 1: Corrosion and Materials