CIP NACE-Level 2. Exam 4 Questions With
100% Verified Correct Answers.
passivation
formation of thin surface layer on metals(oxide, carbonate) that slows the rate of corrosion
process
two categories of corrosion
general and localized
oxygen effect on corrosion
electrolytes w/ different oxygen levels create anodic and cathodic areas of the metal
temperature effect on corrosion
higher temperature results in a greater rate of corrosion
chemical salts effect on corrosion
increase efficiency of electrolye and therefore also the corrosion rate
humidity effect on corrosion
higher ____ results in higher corrosion(usually maxed at 85%)
4 parts of galvanic corrosion
anode, cathode, metallic path, electrolyte
cathodic protection
whole surface is made cathodic with a direct current applied along with a separate anode
crevice corrosion
A form of corrosion that occurs within narrow crevices and under deposits of dirt or corrosion
products (i.e., in regions of localized depletion of oxygen in the solution).
Pitting Corrosion
, Localized corrosion of a metal surface that is confined to a small area and takes the form of
cavities called pits.
galvanic corrosion
is an electrochemical reaction of two disimilar metals in the presence of an electroluye and an
electron conductive path, which occurs when dissimilar metals come into contact
two typs of cathodic protection
galvanic and impressed current
galvanic system
galvanic anode attached to structure
-suitbale materials include aluminum, magnesium and zinc
impressed current system
an external power source is connected or impressed between the structure to be protected and the
ground bed
-examples of materials include scrap steel, graphite, iron oxide, hihg silicon chromium bearing
cast iron, mixed metal oxide titanium
cathodic disbondment
separation of the coating from the surface through OH- ions formation due to increased(i.e made
more negative) potential
sequence of cathodic disbondment
1)stable cathodic protection 2) disbondment by hydroxyl ions 3) disbondent by hydrogen ions
principal component of mild carbon steel
Iron
anode
part of corrosion cell where metal dissolves
most common use for impressed current
100% Verified Correct Answers.
passivation
formation of thin surface layer on metals(oxide, carbonate) that slows the rate of corrosion
process
two categories of corrosion
general and localized
oxygen effect on corrosion
electrolytes w/ different oxygen levels create anodic and cathodic areas of the metal
temperature effect on corrosion
higher temperature results in a greater rate of corrosion
chemical salts effect on corrosion
increase efficiency of electrolye and therefore also the corrosion rate
humidity effect on corrosion
higher ____ results in higher corrosion(usually maxed at 85%)
4 parts of galvanic corrosion
anode, cathode, metallic path, electrolyte
cathodic protection
whole surface is made cathodic with a direct current applied along with a separate anode
crevice corrosion
A form of corrosion that occurs within narrow crevices and under deposits of dirt or corrosion
products (i.e., in regions of localized depletion of oxygen in the solution).
Pitting Corrosion
, Localized corrosion of a metal surface that is confined to a small area and takes the form of
cavities called pits.
galvanic corrosion
is an electrochemical reaction of two disimilar metals in the presence of an electroluye and an
electron conductive path, which occurs when dissimilar metals come into contact
two typs of cathodic protection
galvanic and impressed current
galvanic system
galvanic anode attached to structure
-suitbale materials include aluminum, magnesium and zinc
impressed current system
an external power source is connected or impressed between the structure to be protected and the
ground bed
-examples of materials include scrap steel, graphite, iron oxide, hihg silicon chromium bearing
cast iron, mixed metal oxide titanium
cathodic disbondment
separation of the coating from the surface through OH- ions formation due to increased(i.e made
more negative) potential
sequence of cathodic disbondment
1)stable cathodic protection 2) disbondment by hydroxyl ions 3) disbondent by hydrogen ions
principal component of mild carbon steel
Iron
anode
part of corrosion cell where metal dissolves
most common use for impressed current
