Free API API-571 Practice Test & Real Exam Questions

Exam Code/Number: API-571
Exam Name/Title: Corrosion and Materials Professional
Certification Provider: API
Corresponding Certification: ICP Programs

Exam Questions: 151
Updated On: Jun 24, 2026

Question #31

The primary cause of ammonium chloride corrosion is the formation of salts:

A. During water washing operations in streams containing traces of chlorides

B. That may deposit when water evaporates to dry-out conditions as streams are heated

C. When steam is injected into streams containing traces of chlorides

D. That may precipitate from high-temperature streams as they are cooled

Discussion 0

Correct Answer: D Vote an answer

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Question #32

Corrosion rates of carbon steel pipe in sulfuric acid service increase significantly:

A. At acid concentrations above 95%

B. At acid concentrations below 65%

C. In stagnant conditions

D. At acid concentrations above 65%

Discussion 0

Correct Answer: B Vote an answer

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Question #33

Which of the following weldments is most susceptible to dissimilar metal cracking when operating at high temperatures?

A. Carbon steel to 316 stainless steel

B. Carbon steel to Inconel 625

C. Carbon steel to Incoloy 800

D. Carbon steel to Monel 400

Discussion 0

Correct Answer: A Vote an answer

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Question #34

The likelihood of brittle fracture is best lessened by:

A. Postweld heat treatment (PWHT)

B. Using carbon or low-alloy steels

C. Using thicker construction materials to lower the resulting stress

D. Frequent inspection of the piping or equipment involved

Discussion 0

Correct Answer: A Vote an answer

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Question #35

(Caustic stress corrosion cracking can be effectively prevented by:)

A. The use of a stress-relieving treatment

B. Limiting caustic concentration to less than 100 ppm

C. Limiting metal temperatures to less than 150 °F (65 °C)

D. The use of 300 series stainless steels

Discussion 0

Correct Answer: A Vote an answer

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Question #36

Proactive and retroactive positive material identification programs are especially useful for services exposed to:

A. Sulfidation

B. Ammonia stress corrosion cracking

C. Sour water

D. Caustic embrittlement

Discussion 0

Correct Answer: A Vote an answer

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Question #37

The 300 series stainless steels (austenitic stainless steels) are generally resistant to oxidation up to what temperature?

A. 1600°F (871°C)

B. 1500°F (815°C)

C. 1400°F (760°C)

D. 1300°F (704°C)

Discussion 0

Correct Answer: B Vote an answer

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Question #38

Besides corrosion, what other damage mechanism in hydrofluoric (HF) acid service should inspectors be alert to?

A. Fluoride stress cracking

B. Stress corrosion cracking

C. Hydrogen stress cracking

D. Wet HF cracking

Discussion 0

Correct Answer: C Vote an answer

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Question #39

(Creep damage can be mitigated by:)

A. Removing the damaged material

B. Postweld heat treatment at 1150 °F (621 °C)

C. Preheating to 500 °F (260 °C) during repair welding

D. Solution anneal heat treatment

Discussion 0

Correct Answer: A Vote an answer

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Question #40

Aggressive ammonium chloride corrosion often occurs:

A. When excess water washing dissolves too much ammonium chloride.

B. In the absence of a free water phase.

C. When the salts precipitate from high-temperature streams as they cool.

D. When dry salts are exposed to a small amount of free water.

Discussion 0

Correct Answer: D Vote an answer

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