Low-Cycle Fatigue
Low-cycle fatigue is the fatigue of materials due to repeated, high plastic strains over few load cycles. It leads to failure under low stress.
Physical-Chemical Mechanism of Action
Low-cycle fatigue occurs due to microscopic cracks and grain fusion in the material, which grow under high strain and few load cycles. These processes lead to microcracks that propagate over time and eventually cause material failure.
Metallurgical Relevance & Welding Risks
Low-cycle fatigue can especially occur in highly stressed components like aircraft parts or machine shafts. It increases the susceptibility to cracking and failure under low stress, which can lead to dangerous failures. When welding, it is important to create a homogeneous weld seam to minimize microcrack formation.
Workshop Practice & Instructions
To avoid low-cycle fatigue, pay attention to:
• High weld quality with minimal stress concentration
• Use of high-quality materials with low susceptibility to fatigue
• Control of strain during welding
• Regular testing and inspection of affected components