Exam 1: Corrosion and Materials

Which of the following metals is the most anodic?

MIC is often characterized by _______ within pits in carbon steel.

All ________ based materials and low alloy materials, 300 Series SS and 400 Series SS are susceptible to Sulfidation.

Refractory lined equipment should be designed for erosion, thermal shock and __________.

Increasing chromium content in the alloy improves resistance to sulfidation. However, there is little improvement with increasing chromium content until about ________ Cr.

Carbon steel and low alloy steels are subject to excessive hydrochloric acid corrosion when exposed to any concentration of HCl acid that produces a pH below______.

___________ cooling water outlet temperatures and/or process side outlet temperatures tend to __________ corrosion rates as well as fouling tendency.

_____________ usually occurs when a colder liquid contacts a warmer metal surface.

Sulfidation of iron-based alloys usually begins at metal temperatures above _____.

Sulfidation is primarily caused by:

For galvanic corrosion to take place, three conditions must be met, presence of an electrolyte, two different materials or alloys and ___________.

A form of corrosion that can occur at the junction of dissimilar metals when they are joined together in a suitable electrolyte is __________.

Cracking of dissimilar weld metals occurs in the __________ side of a weld joining 300 Series SS and carbon steel.

Soil corrosion appears as external thinning with localized losses due to _________.

Which of the following alkanolamine systems is the most aggressive in causing amine corrosion?

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

SOHIC is driven by localized stresses so that __________ is somewhat effective in preventing SOHIC damage.

Weld heat affected zone graphitization is most frequently found in the heat affected zone adjacent to welds in a narrow band, corresponding to the low temperature edge of the heat affected zone. In multi-pass welded butt joints, these zones overlap each other covering the entire cross section. Because of its appearance, this type of graphitization is called________.

__________ are the most common type of equipment susceptible to carburization in the refining industry.

SSC is a form of hydrogen stress cracking resulting from the absorption of ________ that is produced by the sulfide corrosion process on the metal surface.