Longitudinal crack
A longitudinal crack runs parallel to the weld and forms due to high longitudinal shrinkage stresses or unsuitable alloys. It leads to brittleness and impairs the mechanical strength of the joint.
Physicochemical Mechanism of Action
A longitudinal crack forms when the weld is pulled too strongly along the joint axis while cooling. Causes can be high stresses in the material or unsuitable additions in the alloy.
Metallurgical Relevance & Welding Risks
A longitudinal crack makes the part brittle and can greatly reduce the mechanical strength of the joint. It can trigger secondary cracks or a complete fracture and so endanger the whole part.
Workshop Practice & Instructions
You avoid longitudinal cracks best by letting the weld cool evenly. Pay attention to suitable cooling technique and use appropriate alloys. With high stresses or critical materials, think about stress-relief methods or protective coatings.