Submerged Arc Welding
- Uses bare wire electrode.
- Fed automatically from spool.
- Generates electric arc to heat metal/
- Flux in powder form.
- Fed using a hopper.
- Electric arc melts joint, flux and electrode.
- Excess flux is collected and re-used.
- Fully automated process.
- Used on Low carbon steels.
- E.g. Ship building and bridge construction.
Resistance Spot welding
- Components to be joined are placed between two non consumable electrodes and pressed together.
- The current is passed through the electrodes which generates the required heat.
- A nugget weld (circular mark) is formed.
- It is used on sheet metals.
- The process is energy efficient and does not require a filler metal.
Resistance Seam welding
- Uses copper rollers to provide a continuous run of overlapping spot welds.
- The current is set at intervals and is generated by a resistance to the flow of an electric current through the parent metals.
- The heat generated depends on time, resistance and current.