Welding Techniques for Different Types of Metals

Different welding techniques are used for welding different metals or alloys, which are described below.

Metal or Alloys
Welding Methods & Techniques
Mild steels or Low carbon steels
  • Forge welding

  • Resistance welding

  • Arc welding

  • Gas welding

  • No flux is required.

  • Welding rods are made up of either mild steel or pure iron.

  • No preheating of work is required.

  • In order to minimize oxidation of steel in gas welding process, a neutral flame is used.

Medium carbon steels (Carbon 0.3% – 0.5%)
  • Arc welding

  • Resistance welding

  • Gas welding

  • Thermit welding

  • Preheating required.

  • The preheating temperature varies from 100 °C to 400 °C, depending upon the carbon content in the steel.

  • A slightly carbonized flame used in gas welding process.

High carbon steel
  • Arc welding

  • Resistance welding

  • Gas welding

  • Thermit welding

  • Preheating of about 400 °C temperature is required.

  • Sudden cooling should be avoided.

  • To relieve the residual stresses, heat treatment of high carbon steels is necessary.

Alloy steels (Contains carbon and small amount of nickel, copper, silicon, manganese, molybdenum, chromium, etc.)
  • Shielded metal arc welding

  • Submerged arc welding

  • Resistance welding

  • Preheating and slow cooling after welding is essential to avoid the cracks in the weld.

Stainless steel
  • Metal arc welding

  • Oxy-acetylene welding

  • Electric butt welding

  • A suitable electrode should be selected.

  • Flux may or may not be used.

  • For obtaining a sound weld, cleaning of edges to be welded and removal of slag after each run is necessary.

Cast steel
  • Gas welding with neutral flame

  • Preheating of heavy casting is essential to minimize straining of metals due to heating during the welding process.

Cast iron
  • Metal arc welding

  • Oxy-acetylene welding

  • Braze welding

  • The cast iron parts are preheated to a dull red heat and then welded.

  • After welding, it is important to anneal the casting.

Aluminum and its alloys
  • Inert gas tungsten arc welding

  • Atomic hydrogen welding

  • All types of inert gas welding

  • For welding of cast aluminum, preheating and slow cooling after welding is necessary.

Copper and its alloys
  • Metal arc welding

  • Carbon arc welding

  • The DC supply with straight polarity is used for welding of copper and its alloys.

  • In gas welding of copper, a neutral flame and a filler rod of copper and silver alloy is used.

Nickel and its alloys
  • Metal arc welding

  • Resistance welding

  • Oxy-acetylene welding

  • Flux is not required.