Drawn Arc Stud Welding
Drawn arc stud welding is an arc welding process for quickly attaching studs to metal surfaces by controlled lifting and plunging of the stud. The process creates a full-area weld in milliseconds.
Physicochemical Mechanism of Action
The drawn arc process uses arc radiation to heat the stud and the workpiece. The temperature rises so quickly that the metal becomes liquid in seconds. The stud is then lifted off controlled and plunged into a prepared weld pool, completing the weld immediately.
Metallurgical Relevance & Welding Risks
Rapid cooling can lead to high stress build-up, which can cause cracks and distortion. It is crucial that the stud and workpiece are heated evenly and simultaneously to ensure a homogeneous weld. Uneven heating or too rapid cooling can lead to glass-hard martensite formation, which increases hardness and reduces toughness.
Workshop Practice & Instructions
• Preparation: The stud and workpiece must be clean and free of dirt and corrosion. Wear appropriate welding protective clothing and respiratory protection.
• Heating: Heat the stud and workpiece simultaneously with the arc. The temperature should rise from normal to liquid state in seconds.
• Lifting and plunging: Lift the stud controlled and insert it into the weld pool while still liquid. This should happen within milliseconds.
• Cooling: Allow the weld to cool naturally after plunging. Avoid any additional cooling methods to ensure homogeneous cooling.