INTRO Flashcards
pervasive problem that affects almost every aspect of our lives, from the cars we
drive to the buildings we live in and the infrastructure we rely on
CORROSION
natural process that involves the deterioration of a material as a result of chemical,
electrochemical or other reactions with its environment.
CORROSION
Corrosion can occur on any material, including
metals, plastics, ceramics, and composites
natural process of deterioration of materials through chemical or electrochemical
reactions with the environment.
Corrosion
It is a complex process that involves the loss of material from a surface due to the interaction
with its surroundings, and it can occur in a variety of forms
Corrosion
Corrosion of metals could also be considered as _________ in reverse
extractive metallurgy
TYPES of CORROSION
Uniform
Galvanic
Pitting
Crevice
Stress corrosion cracking
Fretting
Erosion-corrosion
This is the most common form of corrosion and occurs uniformly across the surface of a metal. It
is often caused by exposure to moisture, chemicals, or other corrosive agents
Uniform
How to prevent uniform corrosion?
Use thicker materials for corrosion allowance
Use paints or metallic coatings such as plating, galvanizing or anodizing
Use Corrosion inhibitors or modifying the environment
occurs when two different metals are in contact with each other and there is
an electrolyte (such as water) present. The more reactive metal (the anode) corrodes more
rapidly than the less reactive metal (the cathode
Galvanic
Localized form of corrosion that creates small, deep holes or pits on the
surface of a metal. It is often caused by the presence of aggressive chemicals or localized differences in the
environment
Pitting
occurs in confined spaces, such as gaps or crevices between metal
surfaces, where oxygen and other chemicals are limited.
Crevice
Crevice corrosion is common in
seawater or other chloride-rich environments.
occurs when a metal is exposed to a corrosive environment and is under
tensile stress.
Stress corrosion cracking
The combination of stress and corrosion can lead to
cracking and failure of the metal.
a type of corrosion that occurs at the interface between two surfaces that are
subjected to cyclic loading or vibration
fretting
Fretting corrosion can cause damage to metal components, such as _________
bolts and bearings
occurs when a metal surface is exposed to a corrosive environment and is also
subjected to mechanical erosion, such as from flowing liquids or particles. This combination can result in accelerated corrosion and damage to the metal.
Erosion corrosion
Examples of erosion corrosion
Ship propellers
Hydraulic turbines
Pump impellers
Diesel engine cylinder
One of the earliest recorded instances of
corrosion control comes from the ancient
____________, who used a technique called
“_____________” to coat metal objects with a
thin layer of gold or silver to protect them
from corrosion
Egyptians, electroplating
The technique involved placing the metal
object in a solution of gold or silver salt
and then passing an electric current
through it to deposit a thin layer of the
precious metal onto the surface
Electroplating
In the middle-ages blacksmiths and
metalworkers would coat__________ with a layer of wax, oil, or tar to prevent them from rusting.
iron and steel objects
In middle ages, they used techniques like _________, which involved heating the
metal to a high temperature and
then quenching it in oil or water, to
create a thin layer of oxide on the
surface of the metal that would help
protect it from further corrosion
bluing
saw significant advances in corrosion control, as engineers and
scientists began to study the mechanisms of corrosion and develop new materials and coatings to
protect against it.
Industrial Revolution
The development of ___________l, for example, was a major breakthrough in corrosion-resistant materials, as it contained a high percentage of ____________, which formed a protective oxide layer
on the surface of the metal
stainless steel, chromium
Corrosion has significant economic and safety implications, as it can cause damage to ________, as well as ___________
infrastructure, equipment, and other assets; pose risks to human health and safety
Economic Implications of corrosion
Maintenance costs
Downtime
Energy consumption
Corrosion can increase maintenance costs
by requiring frequent repairs or
replacements of affected components or
infrastructure.
Maintenance costs
Corrosion-related failures can
cause unexpected downtime, which
can result in lost production,
decreased efficiency, and reduced
profitability for businesses.
Downtime
▪ Corrosion can also increase energy
consumption, as it can cause friction and
resistance in moving parts, leading to
increased wear and tear on equipment and
higher energy usage.
Energy consumption
Safety Implications
Structural integrity
Health risks
Fire hazards
- Corrosion can compromise the
structural integrity of infrastructure
and equipment, leading to potential
collapse or failure
Structural integrity
Corrosion can also pose health
risks, especially if it affects systems
that handle water, chemicals, or
other hazardous materials
Health risks
Corrosion can increase the risk of fires, especially in industrial settings where flammable materials
are present.
Fire hazards
By implementing ____________, businesses and organizations
can reduce the risk of corrosion-related problems and protect their assets and the safety of their
employees and the public
regular inspections, maintenance, and upgrades
