Oxygen activity in the weld pool
Oxygen activity in the weld pool is the chemical potential of dissolved oxygen, which influences surface reactions and oxide formation. Control is essential for defect-free welds.
Physicochemical Mechanism of Action
In the weld pool, there is oxygen that dissolves into the metal and reacts there. The amount of dissolved oxygen determines how strongly oxidation occurs. A high oxygen content leads to rapid oxidation and porosity.
Metallurgical Relevance & Welding Risks
Uncontrolled oxygen content can lead to defective welds. Too much oxygen causes porosity and coarsens the structure, lowering the toughness of the steel. Too little oxygen can cause hot cracking and lack of fusion.
Workshop Practice & Action Instructions
To ensure optimal oxygen activity, monitor the oxygen content in the weld pool precisely. Use deoxidizers such as silicon or titanium steel. Keep the temperature and cooling time constant to regulate the structure. If you lack information on proper control, consult a metallurgist.