Question 1

Amine corrosion depends on the design, operating practices, the type of amine, amine concentration, temperature and _________.

Accepted Answer

A)  Pressure 
B)  Velocity 
C)  Stress 
D)  None of the above

Question 2

Naphthenic acid is _____ by catalytic reactions in downstream hydro processing and FCC units.

Accepted Answer

A)  Enhanced 
B)  Destroyed 
C)  Concentrated 
D)  Diluted

Question 3

Higher __________ containing alloys are used for improved resistance to naphthenic acid corrosion.

Accepted Answer

A)  Chromium 
B)  Carbon 
C)  Molybdenum 
D)  All of the above

Question 4

Corrosion by HF (Hydrofluoric) acid can result in high rates of general or localized corrosion and may be accompanied by hydrogen cracking, blistering and ________.

Accepted Answer

A)  HIC 
B)  Delayed cracking 
C)  SOHIC 
D)  Both A and C

Question 5

Which of the following materials is susceptible to carburization?

Accepted Answer

A)  Low alloy steels 
B)  300 Series SS 
C)  400 Series SS 
D)  All of the above

Question 6

Sulfur and chlorine species in fuel will form sulfur dioxide, sulfur trioxide and hydrogen chloride within the combustion products. At low enough temperatures, these gases and the water vapor in the flue gas will condense to form _________ acid.

Accepted Answer

A)  Hydrochloric 
B)  Hydrofluoric 
C)  Sulfuric 
D)  Both A and C

Question 7

The more noble material, called the ________, is protected by sacrificial corrosion of the more active material, called the ________. The more active metal corrodes at a higher rate than it would if it were not connected to the more noble metal.

Accepted Answer

A)  Anode, Cathode 
B)  Cathode, Anode 
C)  Alpha, Omega 
D)  None of the above

Question 8

Where is PASCC normally located?

Accepted Answer

A)  Adjacent to welds 
B)  On impellers 
C)  At stress risers 
D)  At flanges

Question 9

With sulfidation, the presence of oxygen ________ corrosion

Accepted Answer

A)  Increases 
B)  Decreases 
C)  Has no effect on 
D)  Stops

Question 10

Carbon steel is susceptible to SCC when used in ___________ service.

Accepted Answer

A)  Hydrogen 
B)  Ammonia 
C)  High temperature 
D)  High pressure

Question 11

The sudden rapid fracture under stress (residual or applied) where the material exhibits little or no evidence of ductility or plastic deformation is called _________.

Accepted Answer

A)  885º F Embrittlement 
B)  Temper Embrittlement 
C)  Stress Corrosion Cracking 
D)  Brittle Fracture

Question 12

Sulfidation is also known as ____________.

Accepted Answer

A)  Sulfur corrosion 
B)  Sulfate corrosion 
C)  Sulfidic corrosion 
D)  None of the above

Question 13

Nitriding layers are magnetic. Therefore, _________ should be checked for magnetism as an initial screening for nitriding.

Accepted Answer

A)  300 Series SS 
B)  400 Series SS 
C)  Duplex SS 
D)  Low alloy steel

Question 14

Amine cracking is a form of ________ stress corrosion cracking.

Accepted Answer

A)  Hydrogen 
B)  Caustic 
C)  Polythionic 
D)  Alkaline

Question 15

Corrosion from oxygen in boiler feed water usually creates:

Accepted Answer

A)  Uniform corrosion. 
B)  Isolated pitting. 
C)  Intergranular cracking. 
D)  Transgranular cracking. 
E)  Hard and brittle zones.

Question 16

Temper embrittlement can be identified by a(n) shift in the ductile-to-brittle transition temperature measured in a Charpy impact test.

Accepted Answer

A)  Upward 
B)  Downward 
C)  Abrupt 
D)  None of the above

Question 17

Naphthenic acid corrosion is a form of high temperature corrosion that occurs primarily in crude and vacuum units and downstream units that process certain fractions that contain naphthenic acid. Which of the following materials is susceptible to naphthenic acid corrosion?

Accepted Answer

A)  Carbon steel 
B)  300 Series SS 
C)  400 Series SS 
D)  All of the above

Question 18

__________ is a form of cracking that results when certain molten metals come in contact with specific alloys. Cracking can be very sudden and brittle in nature.

Accepted Answer

A)  SCC 
B)  LME 
C)  AET 
D)  SOHIC

Question 19

In vessels and piping, creep cracking can occur where high metal temperatures and _________ occur together.

Accepted Answer

A)  Pressures 
B)  Stress concentrations 
C)  Velocities 
D)  None of the above

Question 20

Soil to Air interface areas are usually more susceptible to corrosion than the rest of the structure because of ___________ and __________ availability.

Accepted Answer

A)  Moisture 
B)  Bacteria 
C)  Oxygen 
D)  B and C 
E)  A and C

Exam 1: Corrosion and Materials