100% Free API-571 Exam Dumps Use Real ICP Programs Dumps With 112 Questions!
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NEW QUESTION # 25
The rate of spheroidization is affected by:
- A. temperature and microstructure.
- B. temperature and pressure.
- C. exposure time and stress.
- D. type of steel and H# partial pressure.
Answer: A
Explanation:
According to API RP 571 Section 5.3.2.3 (Spheroidization):
"Spheroidization is the transformation of the microstructure of carbon and low alloy steels when exposed to elevated temperatures for long durations. The rate of spheroidization depends on temperature, prior microstructure, and exposure time... The microstructure becomes less effective at carrying loads, and strength is reduced." Key influencing factors for the rate of spheroidization are:
* Temperature (higher accelerates the process),
* Microstructure (initial phase distribution and morphology).
Pressure and hydrogen partial pressure are not relevant for this transformation, nor is stress a primary driver.
Therefore, Option D (temperature and microstructure) is correct.
NEW QUESTION # 26
With sulfidation, the presence of oxygen ________ corrosion
- A. Has no effect on
- B. Decreases
- C. Increases
- D. Stops
Answer: C
NEW QUESTION # 27
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. High
- B. Even
- C. Low
- D. None of the above
Answer: C
NEW QUESTION # 28
The 300 series stainless steels (austenitic stainless steels) are generally resistant to oxidation up to what temperature?
- A. 1300°F (704°C)
- B. 1500°F (815°C)
- C. 1600°F (871°C)
- D. 1400°F (760°C)
Answer: B
Explanation:
According to API RP 571, under Oxidation:
"Austenitic stainless steels (300 Series) are generally used for oxidation resistance up to about 1500°F (815° C). At higher temperatures, scaling and loss of protective chromium oxide layers increase."
"Above these temperatures, specialized high-temperature alloys may be required." (Reference: API RP 571, Section 5.1.1 - Oxidation) Therefore, option C is the correct answer.
NEW QUESTION # 29
Improved resistance to erosion is usually achieved through increasing substrate ________ using harder alloys, hard facing or face-hardening treatment.
- A. Hardness
- B. Composition
- C. None of the above
- D. Stress
Answer: A
NEW QUESTION # 30
Carbonate SCC may easily be mistaken for SSC or SOHIC; however, the carbonate cracks are usually
________ the toe of the weld and have multiple parallel cracks.
- A. Further from
- B. Perpendicular to
- C. Diagonal to
- D. Closer to
Answer: A
NEW QUESTION # 31
_________ material sections also have a ___________ resistance to brittle fracture due to higher constraint, which increases triaxial stresses at the crack tip.
- A. Thinner, Lower
- B. Thicker, Higher
- C. Thinner, Higher
- D. Thicker, Lower
Answer: D
NEW QUESTION # 32
The best method for finding damage from sigma phase embrittlement is:
- A. Ductility testing
- B. Magnetic particle testing
- C. Hardness testing
- D. Metallographic testing
Answer: D
Explanation:
As per API RP 571 on Sigma Phase Embrittlement:
"Sigma phase embrittlement occurs in stainless steels and nickel-based alloys due to the formation of a brittle intermetallic phase in the temperature range of 1050°F to 1650°F (565°C to 900°C)."
"This damage mechanism is not easily detected through surface or hardness testing and typically requires metallographic examination to confirm the presence of sigma phase in the microstructure." Metallographic testing allows clear identification of sigma phase particles and is thus the most reliable method, making option D correct.
NEW QUESTION # 33
Atmospheric corrosion is of greatest concern in:
- A. Wet climates in industrial locations.
- B. Dry climates in industrial locations.
- C. Dry climates in rural locations.
- D. Wet climates in rural locations.
Answer: A
NEW QUESTION # 34
Which if the following materials are not susceptible to hydrogen stress cracking?
- A. Low alloy steel
- B. Carbon steel
- C. None of the above
- D. Stainless steel
Answer: D
NEW QUESTION # 35
(Repeated) The best method for finding damage from sigma phase embrittlement is:
- A. Ductility testing
- B. Magnetic particle testing
- C. Hardness testing
- D. Metallographic testing
Answer: D
Explanation:
Same as above. Sigma phase formation is a microstructural phenomenon and not typically detected by NDE methods like magnetic particle or surface hardness testing.
Therefore, metallographic testing remains the definitive detection method, confirming option D again as the correct answer.
NEW QUESTION # 36
A prime location for erosion is:
- A. Any superheated steam piping.
- B. Upstream of a pump.
- C. In catalyst piping.
- D. Downstream of a gate valve.
Answer: C
NEW QUESTION # 37
With CO(2) corrosion, increasing temperatures _________ corrosion rates up to the point where CO(2) is vaporized.
- A. Increase
- B. Eliminate
- C. Decrease
- D. None of the above
Answer: A
NEW QUESTION # 38
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. CO2
- B. O2
- C. O
- D. H2O
Answer: D
NEW QUESTION # 39
_________ 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. Sensitization
- B. Embrittlement
- C. Graphitization
- D. Carburization
Answer: C
NEW QUESTION # 40
Thermal fatigue is caused by:
- A. Excessive thermal growth.
- B. Hours of physical activity during a hot summer day.
- C. Cyclic stresses that come from temperature variations.
- D. Long term operation at elevated temperatures.
Answer: C
NEW QUESTION # 41
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