Midterm 1st Topic Flashcards
when a refined metal is naturally converted to a more stable form such as its oxide, hydroxide or sulphide state this leads to deterioration of the material
Corrosion
the process resulting from random motion of molecules by which there is a net flow of matter from a region of high concentration to a region of low concentration
Diffusion
– the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius
– indicates the direction in which heat energy will spontaneously flow—i.e., from a hotter body (one at a higher temperature) to a colder body (one at a lower temperature)
Temperature
– a measure of the ability of water to pass an electrical current
– the measure of the ease at which an electric charge or heat can pass through a material
Conductivity
a material which gives very little resistance to the flow of an electric current or thermal energy
Conductor
a chemical substance, usually a liquid, which contains hydrogen and can react with other substances to form salts
Acid
occurs when two dissimilar metals are present in an electrolytic medium
Electrochemical Corrosion
– a chemical compound that dissociates into ions and hence is capable of transporting electric charge - i.e.
– an electric conductor; unlike metals the flow of charge is not a flow of electrons, but is a movement
Electrolyte
Main Factors influencing the Rate of Corrosion
● Diffusion
● Temperature
● Conductivity
● ph (Acid)
● Electrochemical Corrosion/Corrosion Potential
● Types of Ions/Ions
electrically charged atoms
Ions
Two types of ions
Cations & Anions
positively charged ions
Cations
negatively charged ions
Anions
when metals collect this, an electrochemical reaction causes the steel to corrode
Moisture
– also known as metal oxides
– forms when oxygen reacts with metal atoms
Rust