Shielded Metal Arc Welding
Shielded metal arc welding (SMAW) is a manual process using covered stick electrodes, protected by gases and slag. It prevents atmospheric oxidation and allows precise control of the weld.
Physical-Chemical Mechanism of Action
In stick welding, a heavily coated electrode burns in an atmospheric gas mixture above the molten pool. The shielding by gases and slag protects the molten pool from oxidation and allows continuous melting of the metal.
Metallurgical Relevance & Welding Risks
This process is especially suitable for welding thin sheets because it offers high energy output and precise control of the weld. However, too fast cooling can produce hard martensite, leading to cracks and fracture. Too slow cooling increases the risk of grain coarsening and reduced toughness.
Workshop Practice & Action Instructions
For stick welding, use a coated electrode and a gas mixture. Make sure the shielding by gases and slag is stable. Keep the electrode as far as possible from the workpieces to avoid oxidation. Cool the weld slowly to prevent grain coarsening and cracking.