Question 1

Geometry, stress level, _________ and material properties are the predominate factors in determining the fatigue resistance of a component.

Accepted Answer

A)  Temperature 
B)  Pressure 
C)  Velocity 
D)  Number of cycles

Question 2

Contrary to a pure mechanical fatigue, there is no _________ load in corrosion-assistant fatigue. Corrosion promotes failure at a lower stress and number of cycles than the materials normal endurance.

Accepted Answer

A)  Tensile 
B)  Stress 
C)  Ductile 
D)  Fatigue limit

Question 3

The primary factors affecting high temperature oxidation are metal temperature and _______.

Accepted Answer

A)  Pressure 
B)  Alloy composition 
C)  Stress 
D)  Oxygen

Question 4

Preventative measures to minimize the potential for brittle fracture in existing equipment are limited to controlling _______ and ________, minimizing pressure at ambient temperatures during start-up and shutdown and periodic inspections at high stress locations.

Accepted Answer

A)  Temperature, stress 
B)  Stress, pressure 
C)  Velocity, stress 
D)  Temperature, Pressure

Question 5

Temper embrittlement is a metallurgical change that is not readily apparent and can be confirmed through ________.

Accepted Answer

A)  Metallographic examination 
B)  Impact testing 
C)  Metallography 
D)  None of the above

Question 6

Liquid metal embrittlement can occur if 300 Series SS comes in contact with molten _______.

Accepted Answer

A)  Copper 
B)  Mercury 
C)  Zinc 
D)  Lead

Question 7

Which of the following is not a primary factor contributing to erosion?

Accepted Answer

A)  Impact angle (angle that impacting particles strike metal) 
B)  Size of impacting particles 
C)  Velocity of impacting particles 
D)  Density of impacting particles 
E)  Corrosiveness of the environment

Question 8

Which of the methods are effective for finding thermal fatigue cracks?

Accepted Answer

A)  MT 
B)  PT 
C)  VT 
D)  All of the above

Question 9

Carburization can be confirmed by a substantial increase in hardness and a _______ in ductility.

Accepted Answer

A)  Loss 
B)  Gain 
C)  Change 
D)  None of the above

Question 10

Which of the following is not a major factor associated with boiler water condensate corrosion?

Accepted Answer

A)  Operating pressure 
B)  Oxygen content 
C)  Carbon dioxide content 
D)  Process ph 
E)  Temperature

Question 11

The best way to prevent failures by atmospheric corrosion is to:

Accepted Answer

A)  Have an aggressive inspection program. 
B)  Reduce airborne particulates. 
C)  Install and maintain appropriate coatings. 
D)  Shoot all birds that cross the plant fence. 
E)  Build new petrochemical facilities in a dry desert.

Question 12

Cracking of a metal due to stress relaxation during PWHT or in service at elevated temperatures is called ______. It is most often found in heavy wall sections.

Accepted Answer

A)  Thermal cracking 
B)  Reheat cracking 
C)  Step-like cracking 
D)  None of the above

Question 13

A fatigue fracture is brittle and the cracks are most often __________.

Accepted Answer

A)  Parallel 
B)  Transgranular 
C)  Intergranular 
D)  Transverse

Question 14

Inspecting for high-cycle fatigue can be difficult since:

Accepted Answer

A)  The cracks are extremely tight. 
B)  Predicting the location of cracking is difficult. 
C)  Once the crack begins, only a few cycles are needed for the crack to lead to failure. 
D)  Often the equipment is vibrating making non-destructive evaluations difficult.

Question 15

In most cases, brittle fracture occurs only at temperatures below the Charpy impact transition temperature. Steel cleanliness and ________ have a significant influence on toughness and resistance to brittle fracture.

Accepted Answer

A)  Alloy composition 
B)  Tensile strength 
C)  Grain size 
D)  Pressure

Question 16

Sour water corrosion in _________ containing environments may be accompanied by carbonate SCC.

Accepted Answer

A)  H₂O 
B)  H₂S 
C)  CO₂ 
D)  O₂

Question 17

In most cases, brittle fracture occurs only at temperatures _________ the Charpy impact transition temperature.

Accepted Answer

A)  Above 
B)  Below 
C)  Around 
D)  Inside

Question 18

Improved resistance to erosion is usually achieved through increasing substrate ________ using harder alloys, hard facing or face-hardening treatment.

Accepted Answer

A)  Composition 
B)  Stress 
C)  Hardness 
D)  None of the above

Question 19

Amine units are used in refineries to remove H₂S, CO₂ and _________ from process streams originating in many units including the coker, crude, FCC and hydrogen.

Accepted Answer

A)  NA₂ 
B)  Cl₂ 
C)  Mercaptans 
D)  None of the above

Question 20

Which of the following materials is not susceptible to high temperature hydrogen attack?

Accepted Answer

A)  300 Series SS 
B)  5 Cr-1Mo 
C)  9Cr-1Mo 
D)  All of the above

Exam 1: Corrosion and Materials