1. __________ 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 A
2. What structure is 304 stainless steel? A. Martensitic
B. Austenitic C. Duplex D. Ferritic
B
3. _________ is the result of cyclic stress caused by variations in temperature.
A. Creep
B. Thermal Fatigue C. Cyclic Cracking
D. Stress Corrosion Cracking
B
4. 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
C
5. What structure is 410 stainless steel? A. Martensitic
B. Austenitic C. Duplex D. Ferritic
A
6. 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
D
7. What structure is 409 stainless steel? A. Martensitic
B. Austenitic C. Duplex D. Ferritic
D
8. Low alloy steels contain a maximum of _______ chrome. A. 5%
B. 6% C. 7.5% D. 9%
D
9. 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 E
10. For 5Cr-0.5Mo, what is the threshold temperature for creep? A. 500º F B. 800º F C. 600º F D. 700º F B
11. ________ has been a major problem on coke drum shells. A. Thermal fatigue
B. Stress cracking C. Erosion
D. Temper embrittlement
12. Thermal fatigue cracks propagate ________ to the stress and are usually dagger shaped, transgranular and oxide-filled. A. Axial
B. Diagonal C. Transverse D. Angular
C
13. Inspection for wet H2S damage generally focuses on _____ and ______. A. Weld seams B. Nozzles C. Trays D. Down comers E. A and B E
14. ________ 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
B
15. 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
B
16. Which of the following metals is the most anodic? A. Zinc
B. Carbon Steel C. Nickel
D. Monel
A
17. Cracking of dissimilar weld metals occurs on the _________ side of a weld between an austenitic and a Ferritic material operating at high temperatures.
B. Ferritic C. Anodic D. Cathodic
B
18. 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 E
19. 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 E
20. Liquid metal embrittlement can occur if 300 Series SS comes in contact with molten _______.
A. Copper B. Mercury C. Zinc D. Lead
C
21. 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
B
22. 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
A
23. 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
D
24. _____________ usually occurs when a colder liquid contacts a warmer metal surface.
A. Brittle fracture B. Thermal fatigue C. Thermal shock D. Stress rupture
C
25. Nickel based alloys usually contain ________ nickel. A. ≥30%
B. ≥20% C. ≥10% D. ≥12%
A
26. _________ 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
C
27. __________ 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
A
28. With chloride stress corrosion cracking, __________ temperatures ________ the susceptibility for cracking. A. Decreasing, Increases
B. Increasing, Increases C. Increasing, Decreases D. Decreasing, Eliminates
B
29. __________ 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
B
30. 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 A
31. 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
C
32. 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
A
33. Carbon steel is susceptible to SCC when used in ___________ service. A. Hydrogen B. Ammonia C. High temperature D. High pressure B
34. 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 C
35. 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
C
36. 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
D
37. ______ 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
B
38. 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
B
39. 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 D
40. In order for PASCC to occur the material must be ______. A. PWHT
B. Non-PWHT C. Sensitized D. Austenetic
C
41. 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 B
42. Low creep ductility is __________ severe in high tensile strength materials and welds.
A. More B. Less C. Usually D. Not
A
43. _________ is most likely found in hard weld and heat-affected zones and in high strength components.
A. HIC B. SSC C. SOHIC D. Blistering
B
44. At elevated temperature, the carbide phases in certain carbon steels are unstable and may decompose into _______. This decomposition is known as graphitization.
A. Silicon
B. Graphite nodules C. Carbon dust D. Graphite dust
B
45. Hydrogen blisters may form as surface bulges on the ID, the OD on within the wall thickness of a pipe or pressure vessel. Blistering occurs from hydrogen generated by ______, not hydrogen gas from the process stream.
A. H²S B. Corrosion C. Hydriding D. Sulfur
B
46. Since all fuels contain some amount of sulfur, sulfuric and sulfurous acid __________ can occur if the metal
temperature is below this temperature. A. Corrosion
B. Pitting
C. Dew point corrosion D. All of the above
47. The best way to prevent 885º F embrittlement is to use low ________ alloys, or to avoid exposing the susceptible
material to the embrittling range. A. Austenite
B. Martensite C. Ferrite D. Chromium
C
48. The amplitude and frequency of vibration as well as the _________ of the components are critical factors in vibration-induced fatigue. A. Velocity B. Temperature C. Fatigue resistance D. Material properties C
49. Cavitation is best prevented by avoiding conditions that allow the absolute pressure to fall below the ___________ of the liquid or by changing the material properties.
A. Minimum pressure B. Pressure/vapor ratio C. Maximum pressure D. Vapor pressure
D
50. Hardness levels above ________ are highly susceptible to hydrogen stress cracking (HF).Time-to-failure decreases as the hardness increases. A. 225 BHN B. 237 BHN C. 241 BHN D. 247 BHN B
51. __________ are the most common type of equipment susceptible to carburization in the refining industry.
A. Reactors
B. Heat exchangers C. Heater tubes D. Fin Fans
52. Different organisms thrive on different nutrients including inorganic substances (Sulfur, H²S), and organic substances (Hydrocarbons, Organic acids). In addition, all organisms require a source of carbon, nitrogen and _______ for growth. A. Oxygen
B. Water C. Manganese D. Phosphorous
D
53. In design and fabrication, it is advisable to avoid sharp changes in cross section, such as short radius fillets or
undercut that can give rise to _________. Long-seam welds are particularly susceptible to reheat cracking due to mismatch caused by fit up problems.
A. Stress concentrations B. Cracking
C. Circumferential stress D. All of the above
A
54. The most important factors affecting graphitization are the chemistry, stress, temperature and _______.
A. Velocity
B. Time at exposure C. Pressure
D. Ductility
B
55. Creep damage is found in high temperature equipment operating above the ________. Fired heater tubes and components, Catalytic reactors, FCC reactors and FCC fractionator and regenerator internals all operate in or near this.
A. Transition range B. MADT
C. Creep range D. None of the above
C
56. Amine stress corrosion cracking is most often associated with lean amine services. The pure alkanolamine does not cause cracking. Cracking in rich amine services are most often associated with _______ problems.
A. H²S B. Stress
C. Wet H²S D. Temperature
C
57. The loss in strength from spheroidization (Softening) is usually accompanied by a(n) _________ in ductility, which allows for deformation at stress concentrations.
A. Increase B. Decrease C. Reduction D. Yield
A
58. Which of the following materials is not susceptible to high temperature hydrogen attack?
A. 300 Series SS B. 5 Cr-1Mo C. 9Cr-1Mo
D. All of the above
D
59. Which of these materials are susceptible to creep damage? A. Carbon steel
B. Stainless steel C. Low alloy steel D. All of the above
D
60. High temperature hydrogen attack results from exposure to hydrogen at elevated temperatures and pressures. The
hydrogen reacts with __________ in steel to produce
_________, which cannot diffuse through the steel. The loss of carbides causes an overall loss in strength.
A. Carbides, oxygen
B. Alloys, hydrogen dioxide C. Carbides, methane D. Hydrogen dioxide, H²S
C
61. Ferritic stainless steels are usually not used in __________ applications.
A. Non-pressure boundary B. Pressure boundary C. High temperature D. Low temperature
B
62. Stress ruptures are characterized by _________ failures and are usually accompanied by thinning at the fracture surface.
A. Rapid B. Fish-mouth C. Tensile
D. None of the above
B
63. With hydrofluoric acid corrosion, corrosion rates increase with _______ temperatures and ______ HF concentrations. A. Increasing, decreasing
B. Decreasing, increasing C. Increasing, increasing D. Decreasing, decreasing
A
64. Which of the following materials is susceptible to CO² corrosion?
A. Carbon steel B. Stainless steel
C. Duplex stainless steel D. Both B and C
A
65. Steel hardness, __________ and stress are critical factors in causing hydrogen stress cracking.
A. Temperature B. Alloy composition C. Strength
D. None of the above
C
66. If the BHN is 400-500 it may indicate __________. A. Carburization
B. Hydriding
C. Temper embrittlement D. Caustic embrittlement
B
67. The graphitization rate _______ with increasing temperature.
B. Decreases C. Stops D. Proceeds
A
68. The level of creep damage is a function of the material and the coincident _________ level at which the creep
deformation occurs. A. Pressure/Temperature B. Pressure/Stress
C. Temperature/Stress D. None of the above
C
69. Titanium should not be used in known hydriding services such as _____ or ______.
A. Caustic, amine B. Amine, sour water C. Sour water, Alkylation D. All of the above
B
70. Convert these temperatures - 156º C and 450º F A. 304º F, 151º C
B. 284º F, 218º C C. 312º F, 232º C D. 296º F, 246º C
C
71. Which of the following alkanolamine systems is the most aggressive in causing amine corrosion?
A. Monoethanolamine (MEA) B. Diglycolamine (DGA) C. Diethanolamine (DEA)
D. Methyldiethanolamine (MDEA)
A
72. ________ is a loss in toughness due to a metallurgical change that can occur in alloys containing a ferrite phase, as a result of exposure in the temperature range 600º F to 1000º F. A. Caustic embrittlement
B. Notch toughness C. 885º F embrittlement D. Ductile embrittlement
73. 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.
A. O² B. O C. H²O D. CO²
C
74. When connected to a more anodic material, titanium may suffer severe __________. A. Corrosion B. Hydriding C. Stress D. Notch toughness B
75. __________ is a form of stress corrosion cracking normally occurring during shutdowns, startups or during operation when air and moisture are present. Cracking is due to sulfur acids forming from sulfide scale, air and moisture acting on sensitized stainless steel.
A. Caustic SCC B. Chloride SCC
C. Polythionic acid SCC D. None of the above
C
76. ________ usually occurs when a colder liquid contacts a warmer metal surface.
A. Stress cracking B. Thermal fatigue C. Thermal shock D. Stress shock
C
77. Which of these materials is not susceptible to amine cracking?
A. Carbon steel B. 300 Series SS
C. 400 Series SS D. Both B and C
D
78. The presence of ________ in H²S streams increases the severity of high temperature sulfide corrosion at temperatures above about 500º F
A. Amine B. Hydrogen C. Sulfides
D. All of the above
B
79. Increasing chromium content in the alloy improves
resistance to sulfidation. However, there is little improvement with increasing chromium content until about ________ Cr. A. 3-5
B. 5-7 C. 7-9 D. 9-12
C
80. _________ is the sudden rapid fracture under stress (residual or applied) where the material exhibits little or no evidence of ductility or plastic deformation.
A. Thermal fatigue B. Thermal shock C. Brittle fracture D. Stress fracture
C
81. Caustic embrittlement cracking can be effectively prevented by means of PWHT at a temperature of _______. A. 1100º F B. 1150º F C. 1200º F D. 1250º F B
82. General or localized corrosion of carbon steels and other metals caused by dissolved salts, gases, organic compounds or microbiological activity is called _______.
A. Cooling water corrosion B. Oxidation
C. MIC
D. None of the above
A
83. With CO² corrosion, increasing temperatures _________ corrosion rates up to the point where CO² is vaporized.
A. Decrease B. Increase C. Eliminate
D. None of the above
B
84. Units where graphitization may be suspected are the FCCU and the _____ unit.
A. Hydrotreater B. Coker
C. Alky
D. None of the above
B
85. Where is PASCC normally located? A. Adjacent to welds
B. On impellers C. At stress risers D. At flanges
A
86. All ________ based materials and low alloy materials, 300 Series SS and 400 Series SS are susceptible to Sulfidation. A. Carbon
B. Steel C. Chromium D. Iron
D
87. Sulfuric acid promotes general and localized corrosion of carbon steel. Carbon steel heat affected zones may experience severe corrosion. Acid concentration, temperature, alloy content and ____________ are critical factors affecting sulfuric acid corrosion.
A. Pressure B. Stress C. Velocity D. Ductility
88. Which of these materials are susceptible to brittle fracture? A. Carbon steels
B. Low alloy steels C. 400 Series SS D. All of the above
D
89. ____________ is a form of environmental cracking that can initiate on the surface of high strength low alloy steels and carbon steels with highly localized zones of high hardness in the weld metal and HAZ as a result of exposure to aqueous HF acid service.
A. Sulfide stress cracking B. Hydrogen stress cracking C. Caustic stress cracking D. Hydrogen induced cracking
B
90. HCl acid corrosion is found in several units, especially _______ and ________, units, hydroprocessing units and catalytic reformer units.
A. Amine, crude B. Crude, Alkylation C. Vacuum, Amine D. Crude, Vacuum
D
91. Cracking can occur at low caustic levels if a concentrating mechanism is present. In such cases, caustic concentrations of ________ ppm are sufficient to cause cracking.
A. 50-100 B. 100-150 C. 150-200 D. 200-250
A
92. Which of these materials is susceptible to 885º F embrittlement? A. 400 Series SS B. Duplex SS C. 5Cr-1Mo D. Both A and B D
93. Spheroidization and graphitization are competing mechanisms that occur at overlapping temperature ranges. Spheroidization tends to occur preferentially above _______ while graphitization predominates below this temperature. A. 1000º F
B. 1025º F C. 1050º F D. 1100º F
B
94. Sulfidation is primarily caused by ________ and other reactive sulfur species as a result of the thermal decomposition of sulfur compounds at high temperatures.
A. Sulfur dioxide B. H²S
C. Sulfur trioxide D. Sulfates
B
95. Damage from sigma phase appears in the form of ________. A. Corrosion B. Hardness C. Cracking D. Ductility C
96. The extent and depth of decarburization is a function of temperature and ______. A. Pressure B. Material properties C. Exposure time D. Velocity C
97. Corrosion of the anode may be significantly higher ________ to the connection to the cathode, depending on solution conductivity. A. Parallel B. Adjacent C. Diagonally D. Perpendicular B
98. Conditions favoring carburization include a high gas phase carbon activity and _______ oxygen potential.
A. Low B. High C. Negative D. Positive
A
99. Susceptibility to temper embrittlement is largely determined by the presence of the alloying elements manganese and _______.
A. Chromium B. Moly C. Silicon
D. None of the above
C
100. Improved resistance to erosion is usually achieved through increasing substrate ________ using harder alloys, hard facing or face-hardening treatment.
A. Composition B. Stress
C. Hardness
D. None of the above
C
101. Alloys with nickel content above _________ are highly resistant to Cl SCC. The greatest susceptibility is 8% to 12% nickel. A. 15% B. 20% C. 30% D. 35% D
102. _________ corrosion rates are found in a gas oil desulfurizers and hydrocrackers than naphtha desulfurizers and hydrocrackers by a factor of almost "2".
A. Lower B. Higher C. Sulfidization
D. Hydrogen corrosion
103. The accepted way to test for temper embrittlement is ________. A. Impact testing B. Metallographic C. RT D. UT Shear wave A
104. ________ eliminates the susceptibility of most common steels to SCC.
A. Preheat
B. High temperature C. PWHT
D. All of the above
C
105. Changing to a more corrosion resistant and/or higher hardness material _________ improve cavitation resistance. A. Will
B. May C. Will not D. May not
D
106. Dew point corrosion can occur if the metal temperature is below the dew point. The dew point of sulfuric acid is
__________. A. 280º F B. 220º F C. 310º F D. 190º F A
107. All piping and equipment exposed to HF acid at any concentration with hardness levels above ________ are subject to hydrogen stress cracking.
A. 200 BHN B. 210 BHN C. 227 BHN D. 237 BHN
D
108. Cooling water corrosion and __________ are closely related and should be considered together.
B. Velocity C. Fouling D. Erosion
C
109. Which of the following materials is not susceptible to SCC?
A. Carbon steel B. 300 Series SS C. Low alloy steel D. Both A and C
D
110. Graphitization can be prevented by using chromium containing low alloys steels for long-term exposure above ________. A. 650º F B. 700º F C. 750º F D. 800º F D
111. Welds joining dissimilar materials (ferritic and austenetic) may suffer __________ related damage at high temperatures due to differential thermal expansion stresses.
A. Stress B. Creep C. Fatigue
D. Thermal stress
B
112. Carbon steel and low alloy steels are subject to excessive hydrochloric acid corrosion when exposed to any concentration of HCl acid that produces a pH below______.
A. 6.0 B. 5.5 C. 5.0 D. 4.5
D
113. Amine corrosion depends on the design, operating
practices, the type of amine, amine concentration, temperature and _________.
A. Pressure B. Velocity
C. Stress
D. None of the above
B
114. _________ is the main concern during start-up, shutdown and/or hydro testing for equipment/piping
operating at elevated temperatures. This event can also occur in an auto refrigeration event in units processing light
hydrocarbons. A. Stress fracture B. Carburization C. Spheroidization D. Brittle fracture D
115. If wet electrodes or high moisture content flux weld electrodes are used to weld carbon steel, hydrogen can be charged into the steel resulting in _________.
A. Reduced tensile strength B. Loss of ductility
C. Delayed cracking D. All of the above
C
116. Thermal fatigue cracks usually initiate on the _________ of the component. They are generally wide and filled with oxides due to the elevated temperatures.
A. Surface B. ID C. Welds
D. None of the above
A
117. __________ caustic concentrations and ________ temperatures increase the likelihood and severity of cracking with caustic embrittlement.
A. Increasing, Decreasing B. Decreasing, Increasing C. Decreasing, Decreasing D. Increasing, Increasing
D
118. For pressure vessels, inspection should focus on welds of ________ operating in the creep range.
B. Carbon steel C. Stainless steel
D. Low hydrogen electrodes
A
119. With Cl SCC, ________ levels of chloride ________ the likelihood of cracking. A. Decreasing, Increases B. Increasing, Decreases C. Increasing, Increases D. Increasing, Eliminates C
120. Dissimilar weld metal cracking forms at the toe of the weld in the heat affected zone of the ________ material. A. Ferritic
B. Austenitic C. Martensitic D. Both B and C
A
121. The major factors affecting high temperature sulfidation are the temperature, the presence of hydrogen, the
concentration of H²S and the __________. A. Alloy content
B. Velocity C. Pressure D. Water content
A
122. 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 _________.
A. Higher temperatures B. Higher stresses C. Higher pressure D. None of the above
B
123. What standard refers to Risk-Based-Inspection? A. RP 581
B. RP 579 C. RP 588 D. RP 568
124. Carburization can be confirmed by a substantial increase in hardness and a _______ in ductility.
A. Loss B. Gain C. Change
D. None of the above
A
125. In vessels and piping, creep cracking can occur where high metal temperatures and _________ occur together.
A. Pressures
B. Stress concentrations C. Velocities
D. None of the above
B
126. Temper embrittlement _________ be prevented if the material contains critical levels of the embrittling impurity elements and is exposed in the embrittling range.
A. Can B. Cannot C. Will
D. None of the above
B
127. Cl SCC usually occurs at metal temperatures above ________. A. 125º F B. 175º F C. 140º F D. 200º F C
128. Corrosion rates of the anode will be less affected if there is a _________ anode to cathode ratio.
A. Large B. Small C. Severe
D. None of the above
A
129. Hydrogen permeation or diffusion rates have been found to be minimal at pH _______ and increase at both higher and lower pH's.
A. 4 B. 5 C. 6 D. 7
D
130. Cooling water corrosion can result in many different forms of damage including general corrosion, pitting corrosion,
________, stress corrosion cracking and fouling. A. MIC
B. HIC C. SOHIC
D. All of the above
A
131. Ammonium chloride salts may be whitish, greenish or _________. A. Reddish B. Brownish C. Yellowish D. Bluish B
132. Stainless steel cyclones, piping ductwork and valves in high temperature FCC regeneration service are susceptible areas for _________. A. Brittle fracture B. Sigma phase C. Cavitation D. Corrosion fatigue B
133. Non-stressed relieved __________ is susceptible to stress corrosion cracking when in contact with moist HF vapors in the presence of oxygen.
A. Carbon steel B. Alloy 400 C. 300 Series SS D. 400 Series SS
B
134. Higher __________ containing alloys are used for improved resistance to naphthenic acid corrosion.
A. Chromium B. Carbon
C. Molybdenum D. All of the above
C
135. Which material below is not susceptible to caustic corrosion?
A. Carbon steel B. 400 Series SS C. 300 Series SS D. Low alloy steel
B
136. If weld repairs are required, the effects of temper
embrittlement can be temporarily reversed (de-embrittled) by heating at ______ for 2 hours per inch of thickness and rapidly cooling to room temperature.
A. 1000º F B. 1150º F C. 1200º F D. 1250º F
B
137. For carbon steel, common velocity limits are generally limited to _________ fps for rich amine and _______ fps for lean amine.
A. 8-10, 30 B. 6-9, 15 C. 4-8, 10 D. 3-6, 20
D
138. Heat treatment can have a significant effect on the toughness and hence fatigue resistance of a metal. In general, ________ grained microstructures tend to perform better than _________ grained. A. Fine, Course B. Austenetic, martensitic C. Course, Fine D. Martensitic, austenetic A
139. Short term overheating is a permanent deformation occurring at relatively _________ stress levels as a result of localized overheating. This usually results in bulging and failure by stress rupture.
A. Low B. High C. Even
D. None of the above
A
140. Temperature, ________ and stress are critical factors of stress rupture. This is usually found in furnaces with coking tendencies and fired heater tubes.
A. Pressure B. Ductility C. Time
D. Tensile strength
C
141. The effects of hydrogen embrittlement ___________ with _________ temperatures. A. Increase, increasing B. Decrease, decreasing C. Increase, decreasing D. Decrease, increasing D
142. Temper embrittlement can be identified by a(n) shift in the ductile-to-brittle transition temperature measured in a Charpy impact test.
A. Upward B. Downward C. Abrupt
D. None of the above
A
143. Cooling water corrosion is a concern with water-cooled __________ and cooling towers in all applications across all industries. A. Pumps B. Vessels C. Piping D. Exchangers D
144. __________ is a change in the microstructure of steels after exposure in the 850º F to 1400º F range, where the carbide phases in carbon steels are unstable and may agglomerate from their normal plate-like appearance.
A. Carburization B. Spheroidization C. Graphiding
D. 885º Embrittlement
B
145. Corrosion rates of the anode can be high if there is a _______ anode to cathode ratio.
A. Large B. Small C. Severe
D. None of the above
B
146. Application of a post-fabrication stress relieving heat treatment of about ______ is a proven method of preventing carbonate cracking. A. 1100º F B. 1150º F C. 1200º F D. 1250º F B
147. Ammonium chloride corrosion is the general or localized corrosion, often pitting, normally occurring under ammonium chloride or amine salt deposits. All commonly used materials are susceptible to ammonium chloride corrosion. A small amount of _________ can lead to very aggressive corrosion. A. Ammonium chloride
B. Amine C. Water D. Salt
C
148. _________ is a mechanical form of degradation that occurs when a component is exposed to cyclical stresses for an extended period, often resulting in sudden, unexpected failure. A. Stress fatigue
B. Mechanical fatigue C. Thermal fatigue D. Cyclic fatigue
B
149. ________ and _______ damage develop without applied or residual stress so that PWHT will not prevent them
from occurring. A. SOHIC, Blistering B. SCC, SOHIC C. HIC, SCC D. Blistering, HIC D
References
14. Cavitation is a form of erosion caused by the formation and instantaneous collapse of innumerable tiny vapor bubbles.
18. Soil-to-air interface areas are often much more susceptible to corrosion than the rest of the structure because of moisture and oxygen availability (Figure 4-96).
19. Carburization can be confirmed by substantial increases in hardness and loss in ductility
20. LME can only be prevented by protecting metal substrates from coming into contact with the low melting metal. For example, galvanized steel components should not be welded to 300 Series SS. 300 Series SS should be protected to avoid contact with galvanized components and overspray from zinc and inorganic zinc coatings.
22. At high temperatures, metal components can slowly and continuously deform under load below the yield stress. This time dependent deformation of stressed components is known as creep.
23. Permanent deformation occurring at relatively low stress levels as a result of localized overheating. This usually results in bulging and eventually failure by stress rupture.
24. Thermal shock usually occurs when a colder liquid contacts a warmer metal surface.
26. Graphitization is a change in the microstructure of certain carbon steels and 0.5Mo steels after longterm operation in the 800°F to 1100°F (427°C to 593°C) range that may cause a loss in strength, ductility, and/or creep resistance.
27. MIC is usually found in aqueous environments or services where water is always or sometimes present, especially where stagnant or low-flow conditions allow and/or promote the growth of microorganisms.
28. Increasing temperatures increase the susceptibility to cracking. Chloride stress corrosion cracking 29. Liquid Metal Embrittlement (LME) 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.
30. Cracking has been reported down to ambient temperatures with some amines. Increasing temperature and stress levels increases the likelihood and severity of cracking. Refer to API RP 945 for guidelines on PWHT requirements for various amine services.
31. Carbonate stress corrosion cracking can occur at relatively low levels of residual stress but usually occurs at welds or cold worked areas that have not been stress relieved.
