Distributed porosity
Scattered porosity is a uniform or random spread of small gas pockets in weld metal, usually from poor gas shielding.
Physicochemical mechanism of action
Gases such as carbon dioxide or hydrogen can form during welding in the molten pool and in the weld metal. Without adequate degassing through bubble formation or other methods, these gases remain trapped in the metal and form small inclusions.
Metallurgical relevance & risks in welding
These gas inclusions can lead to porosity, which impairs the strength of the weld metal. They can also cause hot cracking or destruction of mechanical properties, especially if they are located in critical areas such as stress zones.
Workshop practice & instructions
To minimize gas porosity, it is important to ensure adequate degassing during welding. This can be achieved by correct selection of the welding method (e.g., TIG welding), proper gas flow, and application of bubble formation techniques. For difficult-to-weld steels or in high stress zones, careful control of degassing processes is essential.