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質問 1：
Severe internal grooving corrosion is found at the bottom of a 4-inch (101.6 mm) carbon steel piping system in steam condensate service. Which of the following is the most likely cause?
A. Carbon dioxide corrosion
B. Ammonium bisulfide corrosion
C. Erosion-corrosion
D. Carbonate corrosion
正解：A
解説: (Pass4Test メンバーにのみ表示されます)
質問 2：
A nickel-based buttering layer is often used when welding austenitic stainless steels to carbon steels to avoid dissimilar weld metal cracking because:
A. The coefficient of thermal expansion is better suited to avoid cracking.
B. You can avoid the need for post weld heat treatment to lower hardness.
C. Nickel base alloys are much softer than austenitic stainless steels.
D. Austenitic stainless steels are susceptible to chloride cracking.
正解：A
解説: (Pass4Test メンバーにのみ表示されます)
質問 3：
Temper embrittlement is a metallurgical change that is:
A. Not readily apparent but can be confirmed through impact testing
B. Readily apparent and can be confirmed through metallography
C. Readily apparent and can be confirmed through impact testing
D. Not readily apparent but can be confirmed through tension testing
正解：A
解説: (Pass4Test メンバーにのみ表示されます)
質問 4：
Which of the following can increase the corrosion rate of carbon steel via hydrofluoric (HF) acid corrosion?
A. Oxygen contamination
B. High nitrogen content in process
C. HF acid concentration above 98%
D. Weld hardness above 200 BHN
正解：D
解説: (Pass4Test メンバーにのみ表示されます)
質問 5：
Which of the following is considered resistant to cracking in hydrofluoric acid service?
A. ASTM A-325
B. ASTM A-193 B7M
C. ASTM A-193 B7
D. ASTM A-193 B5
正解：D
解説: (Pass4Test メンバーにのみ表示されます)
質問 6：
Generally, to minimize corrosion of carbon steel in hydrofluoric acid service, residual elements (Cr, Ni, Cu) should be less than:
A. 0.25 wt.%
B. 0.35 wt.%
C. 0.15 wt.%
D. 0.18 wt.%
正解：C
解説: (Pass4Test メンバーにのみ表示されます)
Severe internal grooving corrosion is found at the bottom of a 4-inch (101.6 mm) carbon steel piping system in steam condensate service. Which of the following is the most likely cause?
A. Carbon dioxide corrosion
B. Ammonium bisulfide corrosion
C. Erosion-corrosion
D. Carbonate corrosion
正解：A
解説: (Pass4Test メンバーにのみ表示されます)
質問 2：
A nickel-based buttering layer is often used when welding austenitic stainless steels to carbon steels to avoid dissimilar weld metal cracking because:
A. The coefficient of thermal expansion is better suited to avoid cracking.
B. You can avoid the need for post weld heat treatment to lower hardness.
C. Nickel base alloys are much softer than austenitic stainless steels.
D. Austenitic stainless steels are susceptible to chloride cracking.
正解：A
解説: (Pass4Test メンバーにのみ表示されます)
質問 3：
Temper embrittlement is a metallurgical change that is:
A. Not readily apparent but can be confirmed through impact testing
B. Readily apparent and can be confirmed through metallography
C. Readily apparent and can be confirmed through impact testing
D. Not readily apparent but can be confirmed through tension testing
正解：A
解説: (Pass4Test メンバーにのみ表示されます)
質問 4：
Which of the following can increase the corrosion rate of carbon steel via hydrofluoric (HF) acid corrosion?
A. Oxygen contamination
B. High nitrogen content in process
C. HF acid concentration above 98%
D. Weld hardness above 200 BHN
正解：D
解説: (Pass4Test メンバーにのみ表示されます)
質問 5：
Which of the following is considered resistant to cracking in hydrofluoric acid service?
A. ASTM A-325
B. ASTM A-193 B7M
C. ASTM A-193 B7
D. ASTM A-193 B5
正解：D
解説: (Pass4Test メンバーにのみ表示されます)
質問 6：
Generally, to minimize corrosion of carbon steel in hydrofluoric acid service, residual elements (Cr, Ni, Cu) should be less than:
A. 0.25 wt.%
B. 0.35 wt.%
C. 0.15 wt.%
D. 0.18 wt.%
正解：C
解説: (Pass4Test メンバーにのみ表示されます)
西村** -
API-571独学者はぜひ参考にしたい内容だなって実感しました。
やっぱり秀逸です。断然お勧めです。