Thermal Efficiency Factor in Welding
The heat input efficiency indicates how much of the applied electrical energy actually transfers into the workpiece. It is crucial for correct calculation of cooling times.
Physicochemical Mechanism of Action
Heat input occurs through the light of the arc, which radiates onto the material. The efficiency describes how much of this energy is actually transferred to the metal body and not lost (e.g., as radiation or heat to the surroundings).
Metallurgical Relevance & Risks When Welding
Low efficiency means less energy goes into the material. This can result in insufficient heating and thus poor weld quality, such as fine grains or low strength. High efficiency, on the other hand, can lead to overheating and dangerous phenomena like grain coarsening or spatter.
Workshop Practice & Action Instructions
To optimize heat input efficiency, take the following measures:
• Adjust the arc: Use an arc with a suitable power factor for the selected material.
• Regulate voltage and current: Adjust the voltage and current of the welding machine to achieve the optimal efficiency.
• Use shielding gases: Using shielding gases can help better control the temperature in the weld zone and increase efficiency.