What is a crater in welding terminology?

In welding terminology, a crater refers to an undesired depression that forms at the end of a weld bead. This feature typically occurs when the welding process is not properly controlled during the final stages of welding, particularly when the arc is extinguished, leading to an uneven surface. The crater can compromise the structural integrity of the weld because it creates a stress concentration point, which may lead to cracking or failure of the weld under load.

Understanding the nature of a crater is crucial for welders, as it highlights the importance of technique and control when finishing a weld to ensure a smooth, continuous transition between the weld and the base material. Addressing this issue often involves adjusting the welding parameters and using techniques such as weaving or manipulating the arc to prevent crater formation.