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

Increasing chromium content in the alloy improves resistance to sulfidation. However, there is little improvement with increasing chromium content until about ________ Cr.

A. 3-5

B. 5-7

C. 7-9

D. 9-12

When carbon is absorbed into a material at elevated temperatures while in contact with a carbonaceous substance it is called carburization. Temperatures usually have to be above __________ for this to occur.

A. 1000º F

B. 1100º F

C. 1200º F

D. 1400º F

With hydrofluoric acid corrosion, corrosion rates increase with _______ temperatures and ______ HF concentrations.

A. Increasing, decreasing

B. Decreasing, increasing

C. Increasing, increasing

D. Decreasing, decreasing

Spheroidization and graphitization are competing mechanisms that occur at overlapping temperature ranges. Spheroidization tends to occur preferentially above _______ while graphitization predominates below this temperature.

A. 1000º F

B. 1025º F

C. 1050º F

D. 1100º F

Weld heat affected zone graphitization is most frequently found in the heataffected zone adjacent to welds in a narrow band, corresponding to the low temperature edge of the heat affected zone, In multi-pass welded butt joints, these zones overlap each other covering the entire cross section. Because of its appearance, this type of graphitization is called________.

A. Half-moon

B. Eyebrow

C. Radii

D. None of the above

Which of the methods are effective for finding thermal fatigue cracks?

A. MT

B. PT

C. VT

D. All of the above

A form of fatigue cracking in which cracks develop under the combined effects of cyclic loading and corrosion is called _______. Cracking often initiates at stress concentrations such as a pit in the surface.

A. Cyclic cracking

B. Corrosion fatigue

C. Stress fatigue

D. Stress cracking

With CO² corrosion, increasing temperatures _________ corrosion rates up to the point where CO² is vaporized.

A. Decrease

B. Increase

C. Eliminate

D. None of the above

Which of the following materials is susceptible to sigma phase embrittlement?

A. Carbon steel

B. Low alloy steel

C. 300 Series SS

D. Both A and B