API API Certifications API-571 Questions & Answers

• Question 391:

  At elevated temperatures, dissimilar weld metal cracking is aggravated by the diffusion of carbon out of the weld metal and into the base metal. The temperature at which carbon diffusion becomes a concern is above ________.

  A. 700º F

  B. 750º F

  C. 800º F

  D. 900º F

  Correct Answer: C

• Question 392:

  Which of the following materials are generally not suitable for HF service?

  A. 300 Series SS

  B. Carbon steel

  C. 400 Series SS

  D. Both A and C

  Correct Answer: D

• Question 393:

  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

  Correct Answer: D

• Question 394:

  With high temperature sulfide corrosion (Sulfidization), noticeable increases may be found downstream of _________ injection points.

  A. Hydrogen

  B. Caustic

  C. Ammonia

  D. Water

  Correct Answer: A

• Question 395:

  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

  Correct Answer: B

• Question 396:

  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

  Correct Answer: A

• Question 397:

  The presence of _________ can destabilize the scale and turn it into a nonprotective scale.

  A. H²S

  B. O²

  C. H²

  D. H²O

  Correct Answer: D

• Question 398:

  Increasing the chromium in steels offers no major improvement in resistance to CO?corrosion until a minimum of __________ is reached.

  A. 9%

  B. 12%

  C. 5%

  D. 7%

  Correct Answer: B

• Question 399:

  Carbonate SCC can occur at relatively low levels of ________ but usually occurs at welds that have not been stressed relieved.

  A. Residual stress

  B. Applied stress

  C. Acid concentration

  D. None of the above

  Correct Answer: A

• Question 400:

  Formation of a metallurgical phase known as sigma phase results in a loss of _________ in some stainless steels as a result of high temperature exposure.

  A. Ductility

  B. Fracture toughness

  C. Embrittlement

  D. None of the above

  Correct Answer: B