Answer:
The importance of ferrite and austenite stabilizing elements in steels .
Explanation:
Alloying -
The process which improves the properties of the steel by changing the chemical composition of the steel via adding some elements .
The properties can be improved by - Stabilizing Austenite and Stabilizing Ferrite .
Stabilizing austenite -
The process by which temperature is increased , in which Austenite exists .
Elements with the same crystal structure as of the austenite ( FCC ) raises its A4 value i.e. the temperature of the formation of austenite from its liquid phase and reduces the value of A3 .
Hence, the elements are -
Cobalt , Nickel , Manganese , Copper.
The examples of the Austenitic steels are -
Hadfield Steel ( 13% Mn , 1.2% Cr , 1% C ) and Austenitic Stainless steel.
Stabilizing ferrite –
The process by which temperature is decreased , in which austenite exists .
Elements with the same crystal structure as of the ferrite (BCC - Cubic body centered ) lowers its A4 value i.e. the temperature of the formation of austenite from its liquid phase and increases the value of A3 .These elements have lower solubility of carbon in austenite, that lead to increase in the amount of carbides in the steel.
Hence, the elements are -
Aluminium , Silicon , Tungsten , Chromium , Molybdenum , Vanadium
The examples of the Ferritic steels are -
F-Cr alloys , transformer sheets steel ( 3% Si ).
