Hot and Cold Working Process of Metals | Advantages and Disadvantages

By | October 22, 2018

In this article we have discussed hot and cold working process of metals. First, we will discuss hot working and then we will discuss cold working of metals.

But before moving to our main topics let us understand one important definition which would be very helpful to us later.

What is recrystallisation temperature?

The temperature at which new stress-free grains are formed in a metal is known as recrystallisation temperature.

We will use this definition later on.

What is Hot working process of metals?

Metal deformation process which is carried out above recrystallisation temperature is known as hot working process.

Examples of hot working processes of metals are hot rolling, hot forging, hot spinning, hot extrusion, hot drawing etc.

Advantages of hot working process

  • It reduces strain hardening
  • Its components have better toughness
  • Its components have better ductility
  • Its components have better resistance to shocks and vibrations
  • Its components have better strength particularly the forged parts
  • It reduces residual stress in the component

Disadvantages of hot working process

  • Rapid oxidation of surface due to high temperature
  • Its components have poor surface finish compared with cold rolled parts
  • It requires expensive tools

What is cold working process of metals?

Metal deformation process which is carried out below recrystallisation temperature is known as cold working process.

Examples of cold working processes of metals are cold rolling, cold forging, cold spinning, cold extrusion, cold drawing etc.

Advantages of cold working

  • Its components have high hardness
  • Its components have high strength
  • Its components have better surface finish compared with the components made by hot working process
  • Its components have high dimensional accuracy
  • Tooling required is comparatively inexpensive

Disadvantages of cold working process

  • It reduces toughness of components
  • It reduces ductility of components
  • Its components have poor resistance to shocks and vibrations
  • It induces residual stress in the parts and proper heat treatment is required to relieve this stress