Question 1

Cracks that are typically straight, non-branching, and devoid of any associated plastic deformation are likely associated with which type of failure?
A) Stress corrosion cracking
B) Brittle fracture
C) Thermal fatigue
D) Temper embrittlement

Accepted Answer

Straight, non-branching cracks with no plastic deformation are a typical characteristic of brittle fracture. Stress corrosion cracking usually exhibits a more irregular crack path, thermal fatigue exhibits multiple branching cracks and Temper Embrittlement is a type of brittle fracture induced by a specific heat treatment.

Question 2

The sudden rapid fracture under stress (residual or applied) where the material exhibits little or no evidence of ductility or plastic deformation is called _________.
A) 885º F Embrittlement
B) Temper Embrittlement
C) Stress Corrosion Cracking
D) Brittle Fracture

Accepted Answer

The description given in the question matches the definition of brittle fracture, which is a sudden and rapid fracture without any significant plastic deformation. The other options (A, B, and C) pertain to specific types of embrittlement or corrosion cracking, but do not cover the general definition of the described phenomenon.

Question 3

At high temperatures, metal components can slowly and continuously deform under load below the yield strength. This time dependent deformation of stressed components is known as _______?
A) Creep
B) Ductility
C) Softening
D) Hardening

Accepted Answer

Creep is the time-dependent deformation of metal under load at high temperatures, below the yield strength. Ductility refers to the ability of a material to withstand plastic deformation without fracturing. Softening and hardening refer to changes in the material's mechanical properties, rather than its time-dependent deformation behavior.

Question 4

Which of the following can be affected by 885º F Embrittlement?
A) 410 SS
B) 430 SS
C) 308 SS
D) Alloy 2205
E) A, B and D

Accepted Answer

885º F Embrittlement affects ferritic and duplex stainless steels, such as 410 SS, 430 SS, and Alloy 2205, due to the formation of brittle phases at this temperature range.

Question 5

Thermal fatigue cracks propagate ________ to the stress and are usually dagger shaped, transgranular and oxide-filled.
A) Axial
B) Diagonal
C) Transverse
D) Angular

Accepted Answer

Thermal fatigue cracks propagate transverse to the stress and are usually dagger-shaped, transgranular, and oxide-filled.

Question 6

Liquid metal embrittlement can occur if 300 Series SS comes in contact with molten _______.
A) Copper
B) Mercury
C) Zinc
D) Lead

Accepted Answer

Liquid metal embrittlement occurs when a liquid metal penetrates the grain boundaries of a metal causing it to become brittle and susceptible to cracking. This can occur when 300 Series SS (stainless steel) comes in contact with molten zinc. Copper, mercury, and lead do not typically cause liquid metal embrittlement in stainless steel.

Question 7

__________ is a change in the microstructure of certain carbon steels and 0.5 Mo steels after long term operation in the 800º F to 1100º F range.
A) Graphitization
B) Softening
C) Temper Embrittlement
D) Creep

Accepted Answer

Graphitization is a change in the microstructure of certain carbon steels and 0.5 Mo steels after long-term operation in the 800º F to 1100º F range, where carbon precipitates as graphite.

Question 8

With CUI, corrosion rates __________ with increasing metal temperatures up to the point where the water evaporates quickly.
A) Decrease
B) Increase
C) Stay the same
D) None of the above

Accepted Answer

With CUI, corrosion rates increase with increasing metal temperatures up to the point where the water evaporates quickly. This is because higher temperatures increase the rate of corrosion reactions.

Question 9

General or localized corrosion of carbon steels and other metals caused by dissolved salts, gases, organic compounds or microbiological activities is called ________.
A) Flue Gas Corrosion
B) Atmospheric Corrosion
C) Cooling Water Corrosion
D) None of the Above
E) All of the Above

Accepted Answer

Cooling water corrosion refers to the general or localized corrosion of metals, including carbon steels, caused by dissolved salts, gases, organic compounds, or microbiological activities in cooling water systems.

Question 10

What structure is 304 stainless steel?
A) Martensitic
B) Austenitic
C) Duplex
D) Ferritic

Accepted Answer

304 stainless steel is an austenitic stainless steel which is the most commonly used stainless steel due to its high corrosion resistance and good formability.

Question 11

________ is a form of erosion caused by the formation and instantaneous collapse of innumerable tiny vapor bubbles.
A) Condensate corrosion
B) Cavitation
C) Dew-Point corrosion
D) Atmospheric corrosion

Accepted Answer

Cavitation is the form of erosion caused by the formation and instantaneous collapse of innumerable tiny vapor bubbles. It occurs in liquid systems where the pressure drops to its vapor pressure, causing the formation of small vapor bubbles that collapse as they move through higher pressure areas. This process can cause damage to surfaces, particularly in pumps and turbines. Condensate corrosion, dew point corrosion, and atmospheric corrosion all involve different mechanisms of corrosion unrelated to cavitation.

Question 12

Which of the following metals is the most anodic?
A) Zinc
B) Carbon Steel
C) Nickel
D) Monel

Accepted Answer

Zinc is the most anodic as it has the lowest electrochemical potential among the given metals. Anodic metals have a tendency to corrode more easily in the presence of a cathodic metal.

Question 13

Inspection for wet H2S damage generally focuses on _____ and ______.
A) Weld seams
B) Nozzles
C) Trays
D) Down comers
E) A and B

Accepted Answer

Weld seams and nozzles are the most common areas for wet H2S damage to occur. Trays and down comers are less susceptible to this type of damage.

Question 14

For 5Cr-0.5Mo, what is the threshold temperature for creep?
A) 500º F
B) 800º F
C) 600º F
D) 700º F

Accepted Answer

The threshold temperature for creep in 5Cr-0.5Mo is typically around 800º F. This means that at temperatures below 800º F, the material will exhibit minimal or no creep deformation, while at temperatures above 800º F, creep deformation will become significant.

Question 15

Soil to Air interface areas are usually more susceptible to corrosion than the rest of the structure because of ___________ and __________ availability.
A) Moisture
B) Bacteria
C) Oxygen
D) B and C
E) A and C

Accepted Answer

Soil to air interface areas are exposed to moisture and oxygen, which can accelerate corrosion. Bacteria may also play a role in corrosion, but it is not as significant as moisture and oxygen.

Question 16

Cracking of dissimilar weld metals occurs on the _________ side of a weld between an austenitic and a Ferritic material operating at high temperatures.
A) Austenitic
B) Ferritic
C) Anodic
D) Cathodic

Accepted Answer

Cracking of dissimilar weld metals occurs on the ferritic side of a weld between an austenitic and a ferritic material operating at high temperatures. This is known as weld metal hot cracking or solidification cracking, and can occur due to differences in thermal expansion coefficients and solidification rates between the two materials.

Question 17

_________ is the result of cyclic stress caused by variations in temperature.
A) Creep
B) Thermal Fatigue
C) Cyclic Cracking
D) Stress Corrosion Cracking

Accepted Answer

Thermal fatigue is the result of cyclic stress caused by variations in temperature. This can lead to cracking and failure of a material over time.

Question 18

Low alloy steels contain a maximum of _______ chrome.
A) 5%
B) 6%
C) 7.5%
D) 9%

Accepted Answer

The answer of Low alloy steels contain a maximum of...

Question 19

________ has been a major problem on coke drum shells.
A) Thermal fatigue
B) Stress cracking
C) Erosion
D) Temper embrittlement

Accepted Answer

Coke drum shells are subjected to extreme temperatures during the coke production process, which can cause thermal cycling and lead to thermal fatigue failure. This is a major problem in coke drum operations. Stress cracking, erosion, and temper embrittlement are also potential issues in coke drum shells, but thermal fatigue is the most commonly observed failure mechanism.

Question 20

Carburization can be confirmed by substantial increases in _______ and loss of __________.
A) Hardness
B) Tensile Strength
C) Ductility
D) A and B
E) A and C

Accepted Answer

Carburization increases hardness due to the introduction of carbon into the surface, which forms hard carbides, and it decreases ductility because the material becomes more brittle.

Exam 1: Corrosion and Materials

Cracks that are typically straight, non-branching, and devoid of any associated plastic deformation are likely associated with which type of failure?

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

At high temperatures, metal components can slowly and continuously deform under load below the yield strength. This time dependent deformation of stressed components is known as _______?

Which of the following can be affected by 885º F Embrittlement?

Thermal fatigue cracks propagate ________ to the stress and are usually dagger shaped, transgranular and oxide-filled.

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

__________ is a change in the microstructure of certain carbon steels and 0.5 Mo steels after long term operation in the 800º F to 1100º F range.

With CUI, corrosion rates __________ with increasing metal temperatures up to the point where the water evaporates quickly.

General or localized corrosion of carbon steels and other metals caused by dissolved salts, gases, organic compounds or microbiological activities is called ________.

What structure is 304 stainless steel?

________ is a form of erosion caused by the formation and instantaneous collapse of innumerable tiny vapor bubbles.

Which of the following metals is the most anodic?

Inspection for wet H2S damage generally focuses on _ and __.

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

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

Cracking of dissimilar weld metals occurs on the _________ side of a weld between an austenitic and a Ferritic material operating at high temperatures.

_________ is the result of cyclic stress caused by variations in temperature.

Low alloy steels contain a maximum of _______ chrome.

________ has been a major problem on coke drum shells.

Carburization can be confirmed by substantial increases in _ and loss of ____.