Question 1

Amine cracking has been reported down to ambient temperatures with some amines. __________ temperatures and stress levels _______ the likelihood and severity of cracking.
A) Increasing increases
B) Increasing, decreases
C) Decreasing increases
D) Increasing, reduces

Accepted Answer

Increasing temperatures and stress levels increase the likelihood and severity of amine cracking due to enhanced chemical activity and stress corrosion.

Question 2

At a given pressure, the H₂S concentration in the sour water _________ as temperature _________.
A) Increases, increases
B) Decreases, decreases
C) Increases, decreases
D) Decreases, increases

Accepted Answer

According to Henry's Law, the solubility of a gas decreases as the temperature increases at a constant pressure. Therefore, as temperature increases, the H₂S concentration in the sour water decreases.

Question 3

Which API RP recommends programs to monitor small-bore piping, flange faces, blistering and HIC/SOHIC in HF alky units?
A) 574
B) 751
C) 571
D) 980

Accepted Answer

API RP 751 provides guidelines for the safe operation of hydrofluoric acid alkylation units, including monitoring and inspection programs for small-bore piping, flange faces, blistering, and HIC/SOHIC.

Question 4

______ is similar to HIC but is a potentially more damaging form of cracking which appears as arrays of cracks stacked on top of each other. The result is a through thickness crack that is perpendicular to the surface and is driven by high levels of stress.
A) MIC
B) SOHIC
C) Sulfuric SCC
D) None of the above

Accepted Answer

SOHIC (Stress-Oriented Hydrogen-Induced Cracking) is a form of cracking that is similar to HIC but more damaging. It appears as stacks of cracks perpendicular to the surface, driven by high levels of stress. MIC (Microbiologically Influenced Corrosion) and Sulfuric SCC (Sulfuric Acid Stress Corrosion Cracking) are forms of corrosion and cracking that are caused by different mechanisms.

Question 5

_________ is a change in the microstructure of certain carbon steels and 0.5Mo steels after long-term operation in the 800º F to 1100º F range that may cause a loss in strength, ductility and/or creep resistance.
A) Embrittlement
B) Carburization
C) Graphitization
D) Sensitization

Accepted Answer

Graphitization is the change in the microstructure of certain carbon steels and 0.5Mo steels after long-term operation in the 800º F to 1100º F range, leading to a loss in strength, ductility, and/or creep resistance.

Question 6

__________ is usually found in aqueous environments or services where water is sometimes or always present, especially where stagnant or low-flow conditions allow the growth of microorganisms.
A) MIC
B) HIC
C) SOHIC
D) None of the above

Accepted Answer

MIC (microbiologically influenced corrosion) is a type of corrosion that occurs in the presence of microorganisms, typically in aqueous environments or areas where water is present and stagnant or low-flow conditions allow for microbial growth. HIC (hydrogen-induced cracking) and SOHIC (stress-oriented hydrogen-induced cracking) are types of corrosion that are caused by hydrogen gas and typically occur in high-pressure environments in the oil and gas industry.

Question 7

The grain size has an important influence on the high temperature ductility and on the reheat cracking susceptibility. A ________ grain size results in _______ ductile heat affected zones, making the material more susceptible to reheat cracking.
A) Large, More
B) Small, Less
C) Large, Less
D) Small, More

Accepted Answer

A large grain size results in less ductile heat affected zones, which makes the material more susceptible to reheat cracking due to reduced ability to accommodate strain.

Question 8

Carbonate stress corrosion cracking usually occurs at welds or cold worked areas that __________.
A) Have been stressed relieved
B) Have not been stressed relieved
C) Have high residual stress
D) Have high-applied stress

Accepted Answer

Carbonate stress corrosion cracking occurs when a material is under tensile stress in the presence of a carbonate or bicarbonate solution. This type of corrosion is often seen in welded or cold worked areas with high residual stress. Therefore, the correct answer is C) Have high residual stress.

Question 9

Nitriding is usually confined to the surface of most components and will have a dull, ______ appearance. In more advanced stages, the material will exhibit very hard surface hardness.
A) Gray
B) Black
C) Brown
D) White

Accepted Answer

Nitriding usually results in a dull gray appearance on the surface of components.

Question 10

Amine stress corrosion cracking is a term applied to the cracking of steels under the combined actions of ________ and __________ in aqueous alkanolamine systems used to remove/absorb H₂S and/or CO₂ and their mixtures from various gas and liquid hydrocarbon streams.
A) Temperature, pressure
B) Pressure, stress
C) Temperature, corrosion
D) Tensile stress, corrosion

Accepted Answer

Amine stress corrosion cracking is caused by the combination of tensile stress and corrosion in alkanolamine systems, which are commonly used to remove H₂S and/or CO₂ from hydrocarbon streams. Temperature and pressure can contribute to the problem, but it is the combination of stress and corrosion that leads to the failure of the steel.

Question 11

Permanent deformation occurring at relatively low stress levels as a result of localized overheating is called ________.
A) Stress cracking
B) Brittle fracture
C) Temper embrittlement
D) Stress rupture

Accepted Answer

Stress rupture is a type of failure that occurs due to prolonged exposure to high temperatures and stress, leading to permanent deformation.

Question 12

Equipment that is temper embrittled may be susceptible to _______ during start-up and shutdown.
A) Creep
B) Thermal fatigue
C) Brittle fracture
D) Stress fatigue

Accepted Answer

Temper embrittlement causes the material to become brittle, increasing the risk of brittle fracture during start-up and shutdown, which involve thermal cycling and rapid changes in stress levels. Creep and stress fatigue are more related to long-term operation under sustained stress, while thermal fatigue is related to cyclic heating and cooling of the material.

Question 13

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

Accepted Answer

Liquid Metal Embrittlement (LME) occurs when certain molten metals come into contact with specific alloys, leading to sudden and brittle cracking.

Question 14

With chloride stress corrosion cracking, __________ temperatures ________ the susceptibility for cracking.
A) Decreasing, Increases
B) Increasing, Increases
C) Increasing, Decreases
D) Decreasing, Eliminates

Accepted Answer

Increasing temperatures generally increase the susceptibility to chloride stress corrosion cracking due to enhanced corrosion kinetics and stress corrosion mechanisms.

Question 15

Low creep ductility is __________ severe in high tensile strength materials and welds.
A) More
B) Less
C) Usually
D) Not

Accepted Answer

High tensile strength materials and welds are more prone to low creep ductility, meaning they are more susceptible to cracking or breaking under prolonged stress at high temperatures.

Question 16

Carbon steel is susceptible to SCC when used in ___________ service.
A) Hydrogen
B) Ammonia
C) High temperature
D) High pressure

Accepted Answer

Carbon steel is susceptible to stress corrosion cracking (SCC) in ammonia service due to the presence of hydrogen, which can lead to embrittlement and cracking.

Question 17

Nickel based alloys usually contain ________ nickel.
A) ≥30%
B) ≥20%
C) ≥10%
D) ≥12%

Accepted Answer

Nickel based alloys usually contain a minimum of 30% nickel. While some alloys may contain lower percentages of nickel, the general consensus is that alloys with less than 30% nickel are not truly considered nickel-based alloys.

Question 18

_____________ usually occurs when a colder liquid contacts a warmer metal surface.
A) Brittle fracture
B) Thermal fatigue
C) Thermal shock
D) Stress rupture

Accepted Answer

Thermal shock occurs when there is a sudden and drastic change in temperature, such as when a colder liquid contacts a warmer metal surface. This can cause thermal stresses and cracking in the metal. Brittle fracture is a type of failure that occurs without prior plastic deformation, and is not necessarily related to temperature changes. Thermal fatigue and stress rupture are both also related to temperature changes, but do not specifically involve a sudden temperature difference as in thermal shock.

Question 19

Weld heat affected zone graphitization is most frequently found in the heat affected zone adjacent to welds in a narrow band, corresponding to the low temperature edge of the heat affected zone. In multi-pass welded butt joints, these zones overlap each other covering the entire cross section. Because of its appearance, this type of graphitization is called________.
A) Half-moon
B) Eyebrow
C) Radii
D) None of the above

Accepted Answer

Weld heat affected zone graphitization that appears as a narrow band adjacent to welds and overlaps in multi-pass welded joints is known as "eyebrow graphitization".

Question 20

In order for PASCC to occur the material must be ______.
A) PWHT
B) Non-PWHT
C) Sensitized
D) Austenitic

Accepted Answer

PASCC (Polythionic Acid Stress Corrosion Cracking) occurs in sensitized materials, particularly in stainless steels that have been exposed to certain environments.

Exam 1: Corrosion and Materials

Amine cracking has been reported down to ambient temperatures with some amines. ____ temperatures and stress levels _ the likelihood and severity of cracking.

At a given pressure, the H₂S concentration in the sour water _ as temperature _.

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

______ is similar to HIC but is a potentially more damaging form of cracking which appears as arrays of cracks stacked on top of each other. The result is a through thickness crack that is perpendicular to the surface and is driven by high levels of stress.

_________ is a change in the microstructure of certain carbon steels and 0.5Mo steels after long-term operation in the 800º F to 1100º F range that may cause a loss in strength, ductility and/or creep resistance.

__________ is usually found in aqueous environments or services where water is sometimes or always present, especially where stagnant or low-flow conditions allow the growth of microorganisms.

The grain size has an important influence on the high temperature ductility and on the reheat cracking susceptibility. A __ grain size results in _ ductile heat affected zones, making the material more susceptible to reheat cracking.

Carbonate stress corrosion cracking usually occurs at welds or cold worked areas that __________.

Nitriding is usually confined to the surface of most components and will have a dull, ______ appearance. In more advanced stages, the material will exhibit very hard surface hardness.

Amine stress corrosion cracking is a term applied to the cracking of steels under the combined actions of and __ in aqueous alkanolamine systems used to remove/absorb H₂S and/or CO₂ and their mixtures from various gas and liquid hydrocarbon streams.

Permanent deformation occurring at relatively low stress levels as a result of localized overheating is called ________.

Equipment that is temper embrittled may be susceptible to _______ during start-up and shutdown.

__________ 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.

With chloride stress corrosion cracking, __ temperatures the susceptibility for cracking.

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

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

Nickel based alloys usually contain ________ nickel.

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

In order for PASCC to occur the material must be ______.