API 571 Exercises, Rev2

API 571 Damage Mechanisms Affecting Fixed Equipment in the Refining Industry

4.2.3 4.2.3 Temper Temper Embri ttl ement 1. Temper Embrittlement is a ________ in toughness that can occur in some low alloy steels. A. increase increase B. decrease 2. Equipment subject to Temper Embrittlement is normally those that operate at ___________. ___________. A. higher temperatur temperatures es B. lower temperatures 3. Temper Embrittlement can be readily found by Visual and other NDE methods. A. True B. False 4. A common method of monitoring for Temper Embrittlement is to _____________ inside the reactor. Samples are periodically removed from these blocks for impact testing to monitor progress of temper embrittlement or until a major repair issue arises. A. install blocks of the original original heats of the alloy alloy steel B. install a block of a similar heat of the alloy steel C. install Temper Embrittlement probes 4.2.7 4.2.7 Bri ttl e Fractu Fractu re 5. Brittle fracture is characterized by ________________________________. A. a slow cracking cracking that that develops develops over an extended extended period period of time B. a high strain rate that leads to a sudden failure C. a sudden rapid failure under stress 6. The main concern for brittle fracture is ______________________. A. during shutdown B. during startup C. during startup and shutdown

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7. Brittle fracture cracks will typically be straight, non-branching, and largely devoid of any associated plastic deformation. A. True B. False 8. Inspection for brittle fracture is______________________________. A. dependent on accessibility to internal surfaces B. dependent on expensive NDE methods such as Acoustic Emissions C. not normally done 4.2.9 Thermal Fatigue 9. The materials subject to thermal fatigue are __________________________. A. high chrome alloys B. all materials of construction C. austenitic stainless steels 10. Thermal fatigue cracks usually initiate _______________of the component. A. on the surface B. in the through thickness C. on the interior 11. Thermal fatigue is best prevented through design and operation to minimize thermal stresses and thermal cycling. Some methods to help prevent thermal fatigue include ____________________________________________. A. blend grinding the weld profile of components to remove stress raisers B. controlled rates of heat during startup and shutdown C. designs that incorporate sufficient flexibility D. All of the above 12. External ________inspection can be used for non-intrusive inspection for internal thermal fatigue cracking and where reinforcing pads prevent nozzle examination. A. Dye penetrant B. Shear Wave UT C. Visual

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4.2.14 Erosion / Erosion-Corrosion 13. Erosion - Corrosion is ______________________________. A. the accelerated mechanical removal of surface material as a result of relative movement between, or impact from solids, liquids, vapor or any combination thereof B. removing protective films or scales by exposing the metal surface to further corrosion 14. Increasing the hardness of the metal substrate is _____________________. A. always a good method to prevent erosion from occurring B. not always a good method to prevent erosion from occurring 15. Visual examination of suspected or troublesome areas, as well as UT checks or RT can be used to detect the extent of metal loss. A. True B. False 16. Which of the following is not a form of erosion or erosion - corrosion? A. cavitation B. fretting C. carburization 4.2.16 Mechanical Failure 17. One of the properties of mechanical fatigue is that it typically happens ___________. A. well below yield strength of the material B. well above yield strength of the material C. at the yield strength of the material 18. Fatigue cracks usually initiate on the surface _______________under cyclic loading. A. at openings only B. at notches or stress raisers C. underneath reinforcement pads only

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19. Heat treatment can have a significant effect on the toughness and hence fatigue resistance of a metal. In general ___________tend to perform better than___________. A. coarse grained microstructures - finer grained B. medium grained microstructures - coarse grained C. finer grained microstructures - coarse grained 20. An example of a component that might exhibit mechanical fatigue due to thermal cycling is a ______________________________________. A. large bore piping systems B. coker drum C. high pressure drop control valves 21. NDE monitoring for mechanical fatigue might include _______________________. A. SWUT, RT and MT B. PT, MT and SWUT C. RT, PT and MT 4.3.2 Atmosp heric Corros ion 22. Materials that might be affected by atmospheric corrosion include ______________. A. Carbon steel, low alloy steels and copper alloyed aluminum B. Carbon steel, low alloy steels and alloyed brasses C. Carbon steel, low alloy steels and the 400 series stainless steels 23. Piping on supports are often very prone to atmospheric corrosion due to ________. A. long horizontal runs B. being located next over sprays and leaks C. water entrapment between the pipe and the supports 24. The method(s) that can be used for inspection to find atmospheric corrosion are_________________. A. Visual and RT B. UT and Visual

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4.3.3 Corrosio n Under Insu latio n (CUI)

25. Materials that might be affected by CUI include_______________________. A. Carbon steel, low alloy steels 300 and 600 Series SS B. Carbon steel, low alloy steels 500 Series SS and duplex stainless steels C. Carbon steel, low alloy steels 300 Series SS and duplex stainless steels 26. It is known that 300 Series SS, 400 Series SS and duplex SS are subject to pitting and localized corrosion. The 300 series are also subject to what form of attack if chlorides are present? A. ________________________________________ 27. Preventing CUI calls for careful selection of insulating materials. Therefore __________ materials will hold less water against the vessel/pipe wall than ___________and, are potentially be less corrosive. A. closed-cell foam glass - mineral wool B. mineral wool - closed-cell foam glass C. asbestos - closed-cell foam glass 28. The recommended technique for identifying wet insulation and potential CUI is ____________. A. Profile radiography B, Neutron backscatter C. Insulation removal 4.3.4 Cooling Water Corrosion 29. Cooling water corrosion is a general or localized corrosion of carbon steels and other metals caused by _______________________________________. A. dissolved salts, gases, organic compounds or microbiological activity B. Low pH, inert gases, inorganic compounds or microbiological activity C. High pH, gases, organic compounds or microbiological activity 30. ________cooling water outlet temperatures and or process side inlet temperatures tend to increase corrosion rates as well as fouling tendency. A. Decreasing B. Increasing

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31. Cooling water corrosion ________areas will appear as grooving along the weld fusion lines. A. at GTAW welds B. at ERW welds C. at nozzle welds 32. Cooling water should be monitored for variables that affect corrosion and fouling. Below list the main variables that affect cooling water corrosion. A. _______________________________ B. _______________________________ C. _______________________________ D. _______________________________ E. _______________________________ F. _______________________________ G. _______________________________ 4.3.5 Boiler Water Condensate Corrosion 33. Corrosion in boiler feed water and condensate return system is usually the result of dissolved gases, such as____________________________. A. oxygen and sulfur phosphates B. carbon dioxide and low pH amine C. oxygen and carbon dioxide 34. Corrosion from oxygen tends to be pitting type damage and can show up any where in the system, but is most aggressive in __________________________. A. equipment such as closed heaters and economizers B. boiler tubes in the radiant section C. boiler tubes in the convection section 35. _______________is the common monitoring tool used to assure that the various treatment systems are performing in a satisfactory manner. A. pH measurement alone B. complete water analysis C. oxygen content

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4.4.2 Sulfidation 36. Which of the following alloys form sulfides at a lower temperature than carbon steel? A. copper alloys B. nickel alloys C. aluminum alloys 37. Generally the resistance to Sulfidation in iron and nickel base alloys increases as the _____________ content increases. A. nickel B. molybdenum C. chromium 38. Inspection methods to determine thinning by Sulfidation include ___and ___. A. UT thickness and VT B. UT thickness and Profile RT C. EC and Profile RT 39. Sulfidation is also known as __________________. A. Sulfurous Oxide Attack (SOA) B. High Temperature Sulfide Attack (HTSA) C. Sulfidic Corrosion (SC) 4.5.1 Chloride Stress Corrosion Cracking (Caustic Embrittl ement) 40. The description of Chloride Stress Corrosion Cracking is surface initiated cracks caused by environmental cracking of 300 Series SS and some nickel base alloys under the combined action of tensile stress, temperature and an aqueous chloride environment. This condition is accelerated by__________. A. increasing temperature B. decreasing temperature C. decreasing chloride 41. Which of the following alloys is highly susceptible to CLSCC? A. nickel B. duplex stainless steel C. 300 series stainless steel

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42. SCC usually occurs at pH values_____. At lower pH values, uniform corrosion generally predominates. SCC tendency decreases toward the alkaline pH region. A. above 2 B. below 2 C. above 4 43. Inspection for CL SCC can be detected by using which of the following NDE methods? A. VT B. PT C. Both methods above 4.5.2 Corr osi on Fatigu e 44. Corrosion fatigue can affect __________________ materials. A. Carbon Steel B. Austenitic Stainless Steel C. All metals and alloys 45. The fatigue fracture is brittle and the cracks are most often _________, as in stresscorrosion cracking, but not branched, and often results in propagation of ____________cracks. A. transgranular - multiple parallel B. intergranular - multiple parallel C. transgranular - multiple radial 46. Corrosion fatigue is usually found in Deaerators by using __________ NDE. A. VT B. MT C. WFMT

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4.5.3 Caustic Stress Corrosio n Cracking (Caustic Embrittl ement) 47. Caustic embrittlement is a form of stress corrosion cracking characterized by surface-initiated cracks that occur in piping and equipment exposed to caustic, primarily adjacent to___________. A. non-PWHT welds B. PWHT welds C. nozzles and other openings 48. Crack propagation rates increase dramatically with temperature and can sometimes grow through wall in ____________________________. A. a matter of a few weeks B. a matter of hours or days C. a matter of a few months 49. Caustic embrittlement is often found in piping and equipment that handles caustic. It may also be found in a process unit that______________________. A. removes naphtha B. mercaptans C. Light Gas Oil 50. Prevention of cracking in carbon steels can be achieved by PWHT to a temperature of __________________. A. 1250 oF B. 1150 oF C. 1300 oF 5.1.2.3 Wet H 2S Damage (Bl isteri ng/HIC/SOHIC/SCC) 51. Name the four types of Wet H 2S Damage. A. ________________________________________________________ B. ________________________________________________________ C. ________________________________________________________ D. ________________________________________________________

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52. Blistering, HIC, and SOHIC damage have been found to occur between ambient and _______________. A. 300oF or higher B. 400oF or higher C. 500oF or higher 53. Typical low-strength carbon steels used in refinery applications should be controlled to produce weld hardness <200 HB. These steels are not usually subject to SCC at hardness below ___________________. A. 200 HB B. 237 HB C. 190 HB 53. Blistering and HIC damage _________ prevented with PWHT. A. cannot be B. can be C. may be 5.1.3.1 High Temperature Hydro gen Attack (HTHA) 54. HTHA occurs when hydrogen reacts with ______in steel to form ______which cannot diffuse through the steel. A. iron - iron oxide B. carbon - carbon dioxide C. carbides - methane 55. Internal visual inspection for blisters ______________ HTHA. A. will always indicate B. may not indicate C. does not indicate 56. Acoustic Emission Testing is a proven method for finding HTHA. A. True B. False

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API 571 Damage Mechanisms Affecting Fixed Equipment in the Refining Industry Answer Key API RP 571 Damage Mechanisms 1. B 2. A 3. B 4. A 5. C 6. C 7. A 8. C 9. B 10. A 11. D 12. B 13. B 14. B 15. A 16. C 17. A 18. B 19. C 20. B 21. B 22. A 23. C 24. B 25. C 26. A. Stress Corrosion Cracking 27. A 28. B 29. A 30. B 31. B 32. A. pH

36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51.

A C B C A C A C C A C A B B B A. Hydrogen Blistering B. Hydrogen Induced Cracking C. Sulfide Stress Corrosion Cracking D. Stress Oriented Hydrogen Induced Cracking

52. 53. 54. 55. 56.

A B C B B

B. Oxygen Content C. Cycles of Concentration D. Biocide Residual E. Biological Activity F. Cooling Water Outlet Temperature G. Hydrocarbon Contamination& Process Leaks

33. 34. 35.

C A B

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API 571 Exercises, Rev2

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