Fracture Appearance
The fracture appearance shows whether there is a brittle cleavage fracture or a tough ductile fracture. It helps in diagnosing material defects and welding problems.
Physical-Chemical Mechanism of Action
The fracture appearance is the visual representation of the material after a fracture. In brittle cleavage fractures, the edges of the cracks are jagged and straight, while tougher ductile fractures have rounded or distorted edges.
Metallurgical Relevance & Risks in Welding
A brittle cleavage fracture often indicates too high a carbon content or too rapid cooling, which leads to martensite. A tough ductile fracture can be caused by excessive stresses or inadequate hardness conditions. Both fracture types can affect the service life and reliability of the component.
Workshop Practice & Instructions
In welding, it is important to respect the critical temperature window (e.g., t8/5 between 5 and 25 seconds). Use suitable shielding gas mixtures to reduce porosity and increase hardness conditions through correct filler materials such as silicon or nickel.