API-571 Online Practice Questions and Answers

Alloys with increased amounts of _______ show improved resistance to naphthenic acid corrosion.

A. Chromium

B. Molybdenum

C. Nickel

D. Carbon

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

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

Which of the following materials is susceptible to carburization?

A. Low alloy steels

B. 300 Series SS

C. 400 Series SS

D. All of the above

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

________ usually occurs when a colder liquid contacts a warmer metal surface.

A. Stress cracking

B. Thermal fatigue

C. Thermal shock

D. Stress shock

Which if the following materials are not susceptible to hydrogen stress cracking?

A. Carbon steel

B. Low alloy steel

C. Stainless steel

D. None of the above

Steel cleanliness and _______ have a significant influence on toughness and resistance to brittle fracture.

A. Composition

B. Alloy

C. Grain size

D. None of the above

Carbonate cracking typically propagates _________ to the weld; the pattern of cracking observed on the surface is sometimes described as ________.

A. Transverse, Eyebrow

B. Parallel, Spider web

C. Diagonal, Half moon

D. Perpendicular, Stair step

Many thermal fatigue cracks are filled with:

A. chlorides.

B. hydroslime.

C. oxides.

D. sulfides.