Weldability: Introduction and Factor Affecting it

• The ease with which welding of a given material can be done without producing any defect is called Weldability.
• Weldability can also be defined as the capability of metal to be welded under the fabrication conditions imposed satisfactorily on the intended surface.
• The metal should not require expensive or complicated or extracting procedures to produce a sound joint.

Factors affecting Weldability:

Melting point, thermal conductivity, reactivity, the coefficient of thermal expansion, electrical resistance and surface condition of material are the factor that affects weldability.

1. Melting point of metal: Materials with a medium melting point can be welded very easily.
2. Thermal conductivity: Material with high thermal conductivity (K) are treated as difficult to weld materials.
3. Reactivity: If the material reacts with air, water or surroundings it becomes difficult to weld.
4. The coefficient of thermal expansion of metals: Material with high thermal expansion coefficient, it becomes difficult to weld.
5. Electrical resistance: Higher the electrical resistance of the material, it becomes difficult because it requires a lot of heat energy.
6. Surface condition: The material with the dirty surface it becomes difficult to weld.

From the above-mentioned factors whichever the material is influenced by a maximum number of factors, the corresponding material is treated as very difficult to weld, and whichever the material is influenced by least number of factors, the corresponding material is treated as very easy weld material.