Schweißrisse

Schweißrisse, also known as welding cracks, are discontinuities that occur in welded joints. They are a type of defect that can significantly reduce the strength and integrity of a welded structure. These cracks can form during or after the welding process, and their formation is influenced by a variety of factors related to the materials being joined, the welding procedure, and the surrounding environment.

The primary cause of schweißrisse is tensile stress that exceeds the material's yield strength. This stress can arise from various sources, including thermal contraction during cooling, restraint from the surrounding base metal or fixture, and residual stresses introduced by the welding process itself. When these stresses are combined with a susceptible material, the crack can initiate and propagate.

Common types of schweißrisse include hot cracks, which form during solidification of the weld metal, and cold cracks, which occur after the weld has cooled, often at room temperature or below. Hot cracks are typically associated with impurities in the weld metal or base material that form low-melting-point phases. Cold cracks, on the other hand, are often related to hydrogen embrittlement, especially in high-strength steels, and can be exacerbated by high cooling rates.

Preventing schweißrisse involves careful consideration of material selection, proper joint design, preheating the base material, selecting appropriate welding consumables with lower susceptibility to cracking, controlling heat input during welding, and implementing post-weld heat treatment. Understanding the potential causes and types of schweißrisse is crucial for ensuring the quality and safety of welded components.