Welding suitability of materials

The weldability of components is largely determined by three factors. This is the “welding suitability” of the material, the “weld safety” of the construction and the “weldability” of the production. The suitability of the material for welding is essentially influenced by:

• the physical properties,
• the chemical composition,
• the surface texture,
• the metallurgical properties.

These are, for example, the strength, the microstructure, the grain size, the roughness, the electrical and thermal conductivity and the melting temperature. Welding suitability is expressed in the welding factor S. Materials with S > 0.8 are considered to have good weldability.

Examples:

• Steel, unalloyed S = 9.05
• Aluminium S = 0.84
• Copper S = 0.186

Values less than 0.3 indicate poor welding suitability.

Literature Tip:  Krause, M.: Widerstandspressschweißen. Schweißtechnische Praxis Bd. 25. DVS-Verlag, Düsseldorf 1993.