Heat treatment is a process used to alter the physical and mechanical properties of metals. There are three main steps: heating, soaking, and cooling. Common heat treatment processes include annealing, normalizing, quenching/hardening, tempering, and surface hardening methods like carburizing and nitriding. Annealing makes metals softer and more machinable by heating below the critical temperature and slow cooling. Normalizing also softens metals by heating above the critical temperature and air cooling. Quenching hardens metals by rapid cooling after heating, making them brittle, which tempering then relieves through lower temperature heating.
2. What is heat treatment process ???
■ Heat treatment is a process in which metal is heated and
cooled in a certain manner to obtain Desire physical and
Mechanical properties
■ Mechanical properties like
hardness,brittleness,toughness,ductility,strength,malleabili
ty etc.
3. What are various is heat treatment
process ???
■ There are basically Three Types of processes
Heating Soaking and Cooling.
■ Under this three processes many processes are
there:-
1. Annealing
2. Normalizing
3. Quenching(Hardening)
4. Tempering
5. Surface hardening
●Carburizing
● Nitriding
4. What is Annealing??
■ It is the process in which the material is heated below its
critical temperature (upto 750°C )for limited time I.e soaking
time and then it is cooled in the Furnace or cooled in
maintained temperature, not cooled gradually in Air
Note:- The material which have high carbon percentage is more
hard and compared to other material.
Advantages:-
■ Structure become more refined
■ Material becomes soft and machineability increases.
5. What is Normalizing??
■ Normalizing is a process in which material is
heated above its critical
temperature(upto950°C) for a limited time or
till soaking time so heat can go inside the
material.
■ After this the material is cooled in
environment I.e directly into air
Advantages:-
■ Our material gets soft but the structure is not
refined compared to Annealing
■ Machineability increses andaterial gets soft
6. What is Quencting or Hardening
process??
■ When the material is heated above its
critical temperature (upto 950°C)and then
it is cooled or Rapid colded in oil or water
depending on the type of process so this
process is known as Quenching
■ Quenching maybe Oil Quenching or Water
Quenching.
Advantages:-
■ Material becomes more harder and brittle
as it is cooled rapidlthe brittle nails can be
removed by tempering process.
7. What is Tempering process??
■ The processed material
which is obtained after
Quenching is again heated
at around 400°C to
500°C so material
becomes soft and the
internal stress being
generated by Rapid
cooling gets relieved and
structure gets refined and
brittleness also reduces.
8. What is Caburizing process??
■ In this process the material
which is obtained by the
above all processes is heated
in carbon atmosphere
furnace so it becomes hard.
■ The carbon content in the
material is increased so the
hardness of the material also
Increasea.
9. What is Nitriding process??
■ According to the type of the requirement
these processes has been carried out.
■ In Nitriding process the material is heated in
the nitrogen atmosphere contain furnace so
the material cover/case or the surface
become harder
