Crater pipe crack
A shrinkage crack at the end of the weld, caused by insufficient crater filling when the arc is extinguished.
Physical-Chemical Mechanism of Action
When the arc is extinguished in the weld zone, a local stress area occurs if the crater is not filled sufficiently. This creates thermal pressure that gives the metal crystals uneven expansion, leading to a stress range.
Metallurgical Relevance & Welding Risks
A shrinkage crack at the end crater can become a weak point in the weld, which can crack or wear under mechanical load. This affects the strength and service life of the joint.
Workshop Practice & Instructions
To avoid shrinkage cracks, it is important to ensure sufficient crater filling. This can be achieved by correctly adjusting the arc and maintaining the right welding parameters. A controlled cooling of the weld and the use of suitable filler materials also help minimize the risk.