manual welding arc (MMA)
Manual welding arc is a welding method in which manual arc welding rods are used for welding. In manual arc welding, the arc generated between the electrode and the workpiece is used to locally heat the electrode and the workpiece to a molten state. The molten droplet at the end of the electrode and the molten base material fuse together to form a molten pool, which moves forward with the arc , The liquid metal in the molten pool gradually cools and crystallizes to form a weld.
The heat-affected zone of manual arc welding is small, it is easy to ensure the quality, the equipment is simple, the operation is flexible, and it can adapt to the process requirements of various welding positions and different plate thicknesses. Now, stainless steel electrodes can basically meet the welding requirements of various stainless steels, and there are almost no restrictions on the selection of electrodes.
Low production efficiency and poor working conditions. The requirements for welders are relatively high. In many cases, welders must have considerable qualifications. The welding deposited metal of some materials does not meet the requirements for use, and the sheet with the thickness of the workpiece generally below 1mm is not suitable for manual arc welding.