API-571 Online Practice Questions and Answers

With steam blanketing, failure occurs as a result of _________ in the tube from the internal steam pressure at the elevated temperature.

A. Stress risers

B. Velocity

C. Hoop stress

D. Tensile strength

Sulfuric acid promotes general and localized corrosion of carbon steel. Carbon steel heat affected zones may experience severe corrosion. Acid concentration, temperature, alloy content and ____________ are critical factors affecting sulfuric acid corrosion.

A. Pressure

B. Stress

C. Velocity

D. Ductility

All piping and equipment exposed to HF acid at any concentration with hardness levels above ________ are subject to hydrogen stress cracking.

A. 200 BHN

B. 210 BHN

C. 227 BHN

D. 237 BHN

For pressure vessels, inspection should focus on welds of ________ operating in the creep range.

A. CrMo alloys

B. Carbon steel

C. Stainless steel D. Low hydrogen electrodes

Cracking of a metal due to stress relaxation during PWHT or in service at elevated temperatures is called ______. It is most often found in heavy wall sections.

A. Thermal cracking

B. Reheat cracking

C. Step-like cracking

D. None of the above

Non-stressed relieved __________ is susceptible to stress corrosion cracking when in contact with moist HF vapors in the presence of oxygen.

A. Carbon steel

B. Alloy 400

C. 300 Series SS

D. 400 Series SS

__________ is a change in the microstructure of certain carbon steels and 0.5 Mo steels after long term operation in the 800º F to 1100º F range.

A. Graphitization

B. Softening

C. Temper Embrittlement

D. Creep

Soil to Air interface areas are usually more susceptible to corrosion than the rest of the structure because of ___________ and __________ availability.

A. Moisture

B. Bacteria

C. Oxygen

D. B and C

E. A and C

In piping and equipment, creep cracking can occur where high metal temperatures and _________ occur together. Creep cracking, once initiated, can progress rapidly.

A. Pressures

B. Stress risers

C. Velocities

D. None of the above

Stainless steels with sigma can normally withstand normal operating stresses but upon cooling to temperatures below _______ may show a complete lack of fracture toughness as measured by a Charpy impact test.

A. 800º F

B. 600º F

C. 500º F

D. 400º F

_________ is the sudden rapid fracture under stress (residual or applied) where the material exhibits little or no evidence of ductility or plastic deformation.

A. Thermal fatigue

B. Thermal shock

C. Brittle fracture

D. Stress fracture

Once cracking from LME has occurred, grinding out the affected area ______ an acceptable fix.

A. Is

B. Is not

C. Can be

D. Can not be

Hardness is primarily an issue with SSC. Typical low strength carbon steels should be controlled to produce weld hardness less than ________.

A. 225 BHN

B. 237 BHN

C. 200 BHN

D. 240 BHN

Many thermal fatigue cracks are filled with:

A. chlorides.

B. hydroslime.

C. oxides.

D. sulfides.

_________ is a mechanical form of degradation that occurs when a component is exposed to cyclical stresses for an extended period, often resulting in sudden, unexpected failure.

A. Stress fatigue

B. Mechanical fatigue

C. Thermal fatigue

D. Cyclic fatigue