Keyhole Welding
Keyhole welding uses high-energy beams or arcs to create a vapor-filled capillary and achieve deep penetration into the material. This allows high welding speeds with minimal distortion.
Physical-Chemical Mechanism of Action
A high-energy beam or arc creates a strongly heated zone in the material that cools quickly and causes deep penetration. This process forms a vapor-filled keyhole through which the weld metal penetrates into the material lattice.
Metallurgical Relevance & Welding Risks
Keyhole welding is especially beneficial for high-performance materials like steel and titanium. It allows high welding speed and minimizes distortion, boosting productivity. However, cooling too fast can lead to glass-hard martensite that's prone to cracking. Cooling too slowly can cause loss of toughness and porosity.
Shop Practice & Instructions
Use a high-energy beam or arc welding machine with proper settings. Make sure the keyhole is clean and the weld metal flow is set right. Cool the weld in a controlled way to get a balanced structure. Typical cooling time is 2 to 5 seconds, depending on material and weld thickness.