Exam 1: Corrosion and Materials

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

Which of the following does not increases the likelihood of atmospheric corrosion?

_________ material sections also have a ___________ resistance to brittle fracture due to higher constraint, which increases triaxial stresses at the crack tip.

Cl SCC usually occurs at metal temperatures above ________.

The major factors affecting high temperature sulfidation are the temperature, the presence of hydrogen, the concentration of H₂S and the __________.

Corrosion in boiler feedwater and condensate return systems is usually the result of dissolved gases, oxygen and ________.

What treatment is used to prevent boiler feed water corrosion?

Characteristic stress corrosion cracks have many branches and may be visually detectable by a __________ appearance on the surface.

Dissimilar metal welds with a 300 Series stainless steel weld metal on a ferritic steel may also result in narrow region of _________ at the toe of the weld, near the fusion line on the ferritic side.

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

Corrosion of carbon steel and other alloys from their reaction with sulfur compounds in high temperature environments is called ______. The presence of hydrogen accelerates corrosion.

___________ is when oxygen reacts with carbon steel and other alloys at high temperatures converting the metal to oxide scale.

Different organisms thrive on different nutrients including inorganic substances (Sulfur, H₂S), and organic substances (Hydrocarbons, Organic acids). In addition, all organisms require a source of carbon, nitrogen and _______ for growth.

The effects of hydrogen embrittlement ___________ with _________ temperatures.

Type 304L SS is satisfactory for phosphoric acid concentration of 100% up to about _________. Type 321 is required from there to 225º F.

Thermal fatigue cracks usually propagate _______ to the stress and they are usually dagger-shaped.

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

Cooling water corrosion and __________ are closely related and should be considered together.

With very few exceptions, cooling water should always be on the ________ side to minimize stagnant areas.

Short term overheating is a permanent deformation occurring at relatively _________ stress levels as a result of localized overheating. This usually results in bulging and failure by stress rupture.