Exam 1: Corrosion and Materials

Low creep ductility is _____ prevalent at the lower temperatures in the creep range. Or low stresses in the upper creep range.

With sulfuric acid corrosion, carbon steel corrosion rates increase significantly if the flow velocity exceeds about ________m fps or at acid concentrations below _________.

In HF service, carbon steel forms a protective _________ scale in dry concentrated acid. Loss of the protective scale through high velocities or turbulence will result in greatly accelerated corrosion rates.

A prime location for erosion is:

________ of a component is the most important factor in determining a components resistance to mechanical fatigue.

Although the loss of toughness from temper embrittlement is not evident at operating temperatures, equipment that is temper embrittled may be susceptible to ________ during start-up and shutdown.

At elevated temperature, the carbide phases in certain carbon steels are unstable and may decompose into _______. This decomposition is known as graphitization.

The regenerator reboiler and the regenerator are areas where the temperature and __________ of the amine stream are the highest and can cause significant corrosion problems.

What structure is 304 stainless steel?

Which of the following can be affected by 885º F Embrittlement?

Dissimilar weld metal cracking occurs because the coefficients of thermal expansion between ferritic steels and 300 Series stainless steels differ by ________ or more.

______ is similar to HIC but is a potentially more damaging form of cracking which appears as arrays of cracks stacked on top of each other. The result is a through thickness crack that is perpendicular to the surface and is driven by high levels of stress.

Phosphoric acid corrosion is usually found in ________ areas.

Mechanical fatigue can cause cracks that initiate from the surface and often form a:

The grain size has an important influence on the high temperature ductility and on the reheat cracking susceptibility. A ________ grain size results in _______ ductile heat affected zones, making the material more susceptible to reheat cracking.

Which of the following is not a major factor associated with corrosion by sulfidation?

Which of the following is not a critical factor that contributes to a brittle fracture?

Damage due to __________ is not visible and can only be observed by metallographic examination.

A minimum of ________ to ______ molybdenum is needed in an alloy to resist naphthenic acid corrosion.

________ and _______ damage develop without applied or residual stress so that PWHT will not prevent them from occurring.