_________ 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
Fatigue will not occur in carbon steel if stresses are below the:
- A . Transition limit.
- B . Endurance limit.
- C . Hardening limit.
- D . Speed limit.
________ has been a major problem on coke drum shells.
- A . Thermal fatigue
- B . Stress cracking
- C . Erosion
- D . Temper embrittlement
The “L” grade of stainless steels will sensitize if exposed more than several hours above _______ or long term above _____.
- A . 1200º F, 800º F
- B . 1000º, 600º F
- C . 1000º F, 750º F
- D . 1100º F, 800º F
Once cracking from LME has occurred, grinding out the affected area ______ an acceptable fix.
- A . Is
- B . Is not
- C . Can be
- D . Can not be
Ferritic stainless steels are usually not used in __________ applications.
- A . Non-pressure boundary
- B . Pressure boundary
- C . High temperature
- D . Low temperature
In general, the resistance of carbon steel and other alloys to High temperature corrosion is determined by the ________ content of the material.
- A . Molybdenum
- B . Chromium
- C . Carbon
- D . All of the above
Conditions favoring carburization include a high gas phase carbon activity and _______ oxygen potential.
- A . Low
- B . High
- C . Negative
- D . Positive
It is generally accepted that stresses approaching _________ are required for SCC to occur so that thermal stress relief is effective in preventing caustic SCC.
- A . MAWP
- B . Yield
- C . Creep range
- D . Critical
Low creep ductility is __________ severe in high tensile strength materials and welds.
- A . More
- B . Less
- C . Usually
- D . Not
Many thermal fatigue cracks are filled with:
- A . chlorides.
- B . hydroslime.
- C . oxides.
- D . sulfides.
Titanium Hydriding damage occurs primarily in sour water strippers and amine units in the overhead condensers, heat exchanger tubes and other titanium equipment operating above _________.
- A . 300º F
- B . 270º F
- C . 210º F
- D . 165º F
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
____________ 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
SOHIC is driven by localized stresses so that __________ is somewhat effective in preventing SOHIC damage.
- A . PWHT
- B . Preheat
- C . Temperature
- D . None of the above
Which of these materials are not susceptible to Spheroidization?
- A . Carbon steel
- B . 9Cr-1Mo
- C . 316 SS
- D . Both A and B
A form of corrosion that can occur at the junction of dissimilar metals when they are joined together in a suitable electrolyte is __________.
- A . Galvanic corrosion
- B . Anodic corrosion
- C . Cathodic corrosion
- D . All of the above
Proper application of ________ will control but not eliminate microbes that cause MIC so that continued treatment is necessary.
- A . Ozone
- B . Caustic
- C . Biocides
- D . None of the above
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
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