Projection Welding
Resistance projection welding is a form of resistance spot welding where preformed projections on the workpiece carry the welding current and control melting precisely at those contact points. It improves weld quality and prevents porosity.
Physical-Chemical Mechanism of Action
The preformed projections on the workpiece concentrate the electric current flow, leading to increased melting performance. Precise control of the melting processes at the projection points enables a homogeneous joint and prevents porosity.
Metallurgical Relevance & Risks in Welding
This method improves weld quality through precise control of the melting processes. Incorrect form or inaccurate control can lead to uneven joints and potential cracks.
Workshop Practice & Instructions
• Projection Forming: The projections must be set up precisely to concentrate the current flow. A faulty setup can lead to uneven melting.
• Current and Time: Regularly check the current and heat time to ensure an optimal joint. Too high can lead to overheating and porosity.